MySQL

Dear MySQL Users, MySQL Cluster is the distributed, shared-nothing variant of MySQL. This storage engine provides: - In-Memory storage - Real-time performance - Transparent Auto-Sharding - Read & write scalability - ... [More] Active-Active/Multi-Master geographic replication - 99.999% High Availability with no single point of failure and on-line maintenance - NoSQL and SQL APIs (including C++, Java, http, Memcached and JavaScript/Node.js) MySQL Cluster 7.4 makes significant advances in performance; operational efficiency (such as enhanced reporting and faster restarts and upgrades) and conflict detection and resolution for active-active replication between MySQL Clusters. MySQL Cluster 7.4.29 has been released and can be downloaded from http://www.mysql.com/downloads/cluster/ where you will also find Quick Start guides to help you get your first MySQL Cluster database up and running. The release notes are available from http://dev.mysql.com/doc/relnotes/mysql-cluster/7.4/en/index.html MySQL Cluster enables users to meet the database challenges of next generation web, cloud, and communications services with uncompromising scalability, uptime and agility. More details can be found at http://www.mysql.com/products/cluster/ Enjoy ! ============================================================================== Changes in MySQL NDB Cluster 7.4.29 (5.6.49-ndb-7.4.29) (2020-07-14, General Availability) MySQL NDB Cluster 7.4.29 is a new release of MySQL NDB Cluster 7.4, based on MySQL Server 5.6 and including features in version 7.4 of the NDB storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases. Obtaining MySQL NDB Cluster 7.4. MySQL NDB Cluster 7.4 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/. For an overview of changes made in MySQL NDB Cluster 7.4, see What is New in NDB Cluster 7.4 ( https://dev.mysql.com/doc/refman/5.6/en/mysql-cluster-what-is-new-7-4.html ). This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes which were added in mainline MySQL 5.6 through MySQL 5.6.49 (see Changes in MySQL 5.6.49 (2020-07-13, General Availability) ( https://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-49.html )). Bugs Fixed * During a node restart, the SUMA block of the node that is starting must get a copy of the subscriptions (events with subscribers) and subscribers (NdbEventOperation instances which are executing) from a node already running. Before the copy is complete, nodes which are still starting ignore any user-level SUB_START or SUB_STOP requests; after the copy is done, they can participate in such requests. While the copy operation is in progress, user-level SUB_START and SUB_STOP requests are blocked using a DICT lock. An issue was found whereby a starting node could participate in SUB_START and SUB_STOP requests after the lock was requested, but before it is granted, which resulted in unsuccessful SUB_START and SUB_STOP requests. This fix ensures that the nodes cannot participate in these requests until after the DICT lock has actually been granted. (Bug #31302657) * An excessive number of entries were written to the backup log when performing an online backup, using ndbmtd on the data nodes. This happened because row changes occurring to fragments managed by LDM instance 1 were always recorded in the log, even when they were for primary fragments other than primary fragments. This wasted resources when restoring from the backup, and could cause other problems when doing so, such as when using staging tables for schema transforms while executing ndb_restore. (Bug #31034270) * The Dojo toolkit included with NDB Cluster and used by the Auto-Installer was upgraded to version 1.15.3. (Bug #31029110) * A packed version 1 configuration file returned by ndb_mgmd could contain duplicate entries following an upgrade to NDB 8.0, which made the file incompatible with clients using version 1. This occurs due to the fact that the code for handling backwards compatibility assumed that the entries in each section were already sorted when merging it with the default section. To fix this, we now make sure that this sort is performed prior to merging. (Bug #31020183) * When executing any of the SHUTDOWN, ALL STOP, or ALL RESTART management commands, it is possible for different nodes to attempt to stop on different global checkpoint index (CGI) boundaries. If they succeed in doing so, then a subsequent system restart is slower than normal because any nodes having an earlier stop GCI must undergo takeover as part of the process. When nodes failing on the first GCI boundary cause surviving nodes to be nonviable, surviving nodes suffer an arbitration failure; this has the positive effect of causing such nodes to halt at the correct GCI, but can give rise to spurious errors or similar. To avoid such issues, extra synchronization is now performed during a planned shutdown to reduce the likelihood that different data nodes attempt to shut down at different GCIs as well as the use of unnecessary node takeovers during system restarts. (Bug #31008713) On Behalf of MySQL Release Engineering Team, Surabhi Bhat [Less]

Dear MySQL Users, MySQL Cluster is the distributed, shared-nothing variant of MySQL. This storage engine provides: - In-Memory storage - Real-time performance (with optional checkpointing to disk) - Transparent Auto-Sharding - Read & ... [More] write scalability - Active-Active/Multi-Master geographic replication - 99.999% High Availability with no single point of failure and on-line maintenance - NoSQL and SQL APIs (including C++, Java, http, Memcached and JavaScript/Node.js) MySQL Cluster 7.5.19 has been released and can be downloaded from http://www.mysql.com/downloads/cluster/ where you will also find Quick Start guides to help you get your first MySQL Cluster database up and running. The release notes are available from http://dev.mysql.com/doc/relnotes/mysql-cluster/7.5/en/index.html MySQL Cluster enables users to meet the database challenges of next generation web, cloud, and communications services with uncompromising scalability, uptime and agility. More details can be found at http://www.mysql.com/products/cluster/ Enjoy ! ============================================================================== Changes in MySQL NDB Cluster 7.5.19 (5.7.31-ndb-7.5.19) (2020-07-14, General Availability) MySQL NDB Cluster 7.5.19 is a new release of MySQL NDB Cluster 7.5, based on MySQL Server 5.7 and including features in version 7.5 of the NDB (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster.html) storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases. Obtaining MySQL NDB Cluster 7.5. MySQL NDB Cluster 7.5 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/. For an overview of changes made in MySQL NDB Cluster 7.5, see What is New in NDB Cluster 7.5 (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-what-is-new-7-5.html). This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes which were added in mainline MySQL 5.7 through MySQL 5.7.31 (see Changes in MySQL 5.7.31 (2020-07-13, General Availability) (https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-31.html)). Bugs Fixed * During a node restart, the SUMA (https://dev.mysql.com/doc/ndb-internals/en/ndb-internals-kernel-blocks-suma.html) block of the node that is starting must get a copy of the subscriptions (events with subscribers) and subscribers (NdbEventOperation (https://dev.mysql.com/doc/ndbapi/en/ndb-ndbeventoperation.html) instances which are executing) from a node already running. Before the copy is complete, nodes which are still starting ignore any user-level SUB_START or SUB_STOP requests; after the copy is done, they can participate in such requests. While the copy operation is in progress, user-level SUB_START and SUB_STOP requests are blocked using a DICT (https://dev.mysql.com/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbdict.html) lock. An issue was found whereby a starting node could participate in SUB_START and SUB_STOP requests after the lock was requested, but before it is granted, which resulted in unsuccessful SUB_START and SUB_STOP requests. This fix ensures that the nodes cannot participate in these requests until after the DICT (https://dev.mysql.com/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbdict.html) lock has actually been granted. (Bug #31302657) * Statistics generated by NDB for use in tracking internal objects allocated and deciding when to release them were not calculated correctly, with the result that the threshold for resource usage was 50% higher than intended. This fix corrects the issue, and should allow for reduced memory usage. (Bug #31127237) * An excessive number of entries were written to the backup log when performing an online backup, using ndbmtd on the data nodes. This happened because row changes occurring to fragments managed by LDM instance 1 were always recorded in the log, even when they were for primary fragments other than primary fragments. This wasted resources when restoring from the backup, and could cause other problems when doing so, such as when using staging tables for schema transforms while executing ndb_restore. (Bug #31034270) * The Dojo toolkit included with NDB Cluster and used by the Auto-Installer was upgraded to version 1.15.3. (Bug #31029110) * A packed version 1 configuration file returned by ndb_mgmd could contain duplicate entries following an upgrade to NDB 8.0, which made the file incompatible with clients using version 1. This occurs due to the fact that the code for handling backwards compatibility assumed that the entries in each section were already sorted when merging it with the default section. To fix this, we now make sure that this sort is performed prior to merging. (Bug #31020183) * When executing any of the SHUTDOWN (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-mgm-client-commands.html#ndbclient-shutdown), ALL STOP (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-mgm-client-commands.html#ndbclient-stop), or ALL RESTART (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-mgm-client-commands.html#ndbclient-restart) management commands, it is possible for different nodes to attempt to stop on different global checkpoint index (CGI) boundaries. If they succeed in doing so, then a subsequent system restart is slower than normal because any nodes having an earlier stop GCI must undergo takeover as part of the process. When nodes failing on the first GCI boundary cause surviving nodes to be nonviable, surviving nodes suffer an arbitration failure; this has the positive effect of causing such nodes to halt at the correct GCI, but can give rise to spurious errors or similar. To avoid such issues, extra synchronization is now performed during a planned shutdown to reduce the likelihood that different data nodes attempt to shut down at different GCIs as well as the use of unnecessary node takeovers during system restarts. (Bug #31008713) * The master node in a backup shut down unexpectedly on receiving duplicate replies to a DEFINE_BACKUP_REQ signal. These occurred when a data node other than the master errored out during the backup, and the backup master handled the situation by sending itself a DEFINE_BACKUP_REF signal on behalf of the missing node, which resulted in two replies being received from the same node (a CONF signal from the problem node prior to shutting down and the REF signal from the master on behalf of this node), even though the master expected only one reply per node. This scenario was also encountered for START_BACKUP_REQ and STOP_BACKUP_REQ signals. This is fixed in such cases by allowing duplicate replies when the error is the result of an unplanned node shutdown. (Bug #30589827) * A BLOB value is stored by NDB in multiple parts; when reading such a value, one read operation is executed per part. If a part is not found, the read fails with a row not found error, which indicates a corrupted BLOB, since a BLOB should never have any missing parts. A problem can arise because this error is reported as the overall result of the read operation, which means that mysqld sees no error and reports zero rows returned. This issue is fixed by adding a check specifically for the case in which a blob part is not found. Now, when this occurs, overwriting the row not found error with corrupted blob, which causes the originating SELECT (https://dev.mysql.com/doc/refman/5.7/en/select.html) statement to fail as expected. Users of the NDB API should be aware that, despite this change, the NdbBlob::getValue() (https://dev.mysql.com/doc/ndbapi/en/ndb-ndbblob-getvalue.html) method continues to report the error as row not found in such cases. (Bug #28590428) * Incorrect handling of operations on replicas during node restarts could result in a forced shutdown, or in content diverging between replicas, when primary keys with nonbinary (case-sensitive) equality conditions were used. (Bug #98526, Bug #30884622) On Behalf of Oracle/MySQL Release Engineering Team, Sreedhar S [Less]

Dear MySQL Users, MySQL Cluster is the distributed, shared-nothing variant of MySQL. This storage engine provides: - In-Memory storage - Real-time performance (with optional checkpointing to disk) - Transparent Auto-Sharding - Read ... [More] & write scalability - Active-Active/Multi-Master geographic replication - 99.999% High Availability with no single point of failure and on-line maintenance - NoSQL and SQL APIs (including C++, Java, http, Memcached and JavaScript/Node.js) MySQL Cluster 7.6.15 has been released and can be downloaded from https://www.mysql.com/downloads/cluster/ where you will also find Quick Start guides to help you get your first MySQL Cluster database up and running. MySQL Cluster 7.6 is also available from our repository for Linux platforms, go here for details: https://dev.mysql.com/downloads/ The release notes are available from https://dev.mysql.com/doc/relnotes/mysql-cluster/7.6/en/ MySQL Cluster enables users to meet the database challenges of next generation web, cloud, and communications services with uncompromising scalability, uptime and agility. More details can be found at https://www.mysql.com/products/cluster/ Enjoy ! ============================================================================== Changes in MySQL NDB Cluster 7.6.15 (5.7.31-ndb-7.6.15) (2020-07-14, General Availability) MySQL NDB Cluster 7.6.15 is a new release of NDB 7.6, based on MySQL Server 5.7 and including features in version 7.6 of the NDB storage engine, as well as fixing recently discovered bugs in previous NDB Cluster releases. Obtaining NDB Cluster 7.6. NDB Cluster 7.6 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/. For an overview of changes made in NDB Cluster 7.6, see What is New in NDB Cluster 7.6 (https://dev.mysql.com/doc/refman/5.7/en/mysql-cluster-what-is-new-7-6.html). This release also incorporates all bug fixes and changes made in previous NDB Cluster releases, as well as all bug fixes and feature changes which were added in mainline MySQL 5.7 through MySQL 5.7.31 (see Changes in MySQL 5.7.31 (2020-07-13, General Availability) (https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-31.html)). Bugs Fixed * NDB Disk Data: ndbmtd sometimes terminated unexpectedly when it could not complete a lookup for a log file group during a restore operation. (Bug #31284086) * NDB Disk Data: An uninitialized variable led to issues when performing Disk Data DDL operations following a restart of the cluster. (Bug #30592528) * ndb_restore --remap-column did not handle columns containing NULL values correctly. Now any offset specified by the mapping function used with this option is not applied to NULL, so that NULL is preserved as expected. (Bug #31966676) * MaxDiskWriteSpeedOwnRestart was not honored as an upper bound for local checkpoint writes during a node restart. (Bug #31337487) References: See also: Bug #29943227. * During a node restart, the SUMA block of the node that is starting must get a copy of the subscriptions (events with subscribers) and subscribers (NdbEventOperation instances which are executing) from a node already running. Before the copy is complete, nodes which are still starting ignore any user-level SUB_START or SUB_STOP requests; after the copy is done, they can participate in such requests. While the copy operation is in progress, user-level SUB_START and SUB_STOP requests are blocked using a DICT lock. An issue was found whereby a starting node could participate in SUB_START and SUB_STOP requests after the lock was requested, but before it is granted, which resulted in unsuccessful SUB_START and SUB_STOP requests. This fix ensures that the nodes cannot participate in these requests until after the DICT lock has actually been granted. (Bug #31302657) * DUMP 1001 (DumpPageMemoryOnFail) now prints out information about the internal state of the data node page memory manager when allocation of pages fails due to resource constraints. (Bug #31231286) * Statistics generated by NDB for use in tracking internal objects allocated and deciding when to release them were not calculated correctly, with the result that the threshold for resource usage was 50% higher than intended. This fix corrects the issue, and should allow for reduced memory usage. (Bug #31127237) * An excessive number of entries were written to the backup log when performing an online backup, using ndbmtd on the data nodes. This happened because row changes occurring to fragments managed by LDM instance 1 were always recorded in the log, even when they were for primary fragments other than primary fragments. This wasted resources when restoring from the backup, and could cause other problems when doing so, such as when using staging tables for schema transforms while executing ndb_restore. (Bug #31034270) * The Dojo toolkit included with NDB Cluster and used by the Auto-Installer was upgraded to version 1.15.3. (Bug #31029110) * A packed version 1 configuration file returned by ndb_mgmd could contain duplicate entries following an upgrade to NDB 8.0, which made the file incompatible with clients using version 1. This occurs due to the fact that the code for handling backwards compatibility assumed that the entries in each section were already sorted when merging it with the default section. To fix this, we now make sure that this sort is performed prior to merging. (Bug #31020183) * When executing any of the SHUTDOWN, ALL STOP, or ALL RESTART management commands, it is possible for different nodes to attempt to stop on different global checkpoint index (CGI) boundaries. If they succeed in doing so, then a subsequent system restart is slower than normal because any nodes having an earlier stop GCI must undergo takeover as part of the process. When nodes failing on the first GCI boundary cause surviving nodes to be nonviable, surviving nodes suffer an arbitration failure; this has the positive effect of causing such nodes to halt at the correct GCI, but can give rise to spurious errors or similar. To avoid such issues, extra synchronization is now performed during a planned shutdown to reduce the likelihood that different data nodes attempt to shut down at different GCIs as well as the use of unnecessary node takeovers during system restarts. (Bug #31008713) * When responding to a SCANTABREQ, an API node can provide a distribution key if it knows that the scan should work on only one fragment, in which case the distribution key should be the fragment ID, but in some cases a hash of the partition key was used instead, leading to failures in DBTC. (Bug #30774226) * Several memory leaks found in ndb_import have been removed. (Bug #30756434, Bug #30727956) * The master node in a backup shut down unexpectedly on receiving duplicate replies to a DEFINE_BACKUP_REQ signal. These occurred when a data node other than the master errored out during the backup, and the backup master handled the situation by sending itself a DEFINE_BACKUP_REF signal on behalf of the missing node, which resulted in two replies being received from the same node (a CONF signal from the problem node prior to shutting down and the REF signal from the master on behalf of this node), even though the master expected only one reply per node. This scenario was also encountered for START_BACKUP_REQ and STOP_BACKUP_REQ signals. This is fixed in such cases by allowing duplicate replies when the error is the result of an unplanned node shutdown. (Bug #30589827) * When updating NDB_TABLE comment options using ALTER TABLE, other options which has been set to non-default values when the table was created but which were not specified in the ALTER TABLE statement could be reset to their defaults. See Setting NDB_TABLE Options (https://dev.mysql.com/doc/refman/5.7/en/create-table-ndb-table-comment-options.html), for more information. (Bug #30428829) * When, during a restart, a data node received a GCP_SAVEREQ signal prior to beginning start phase 9, and thus needed to perform a global checkpoint index write to a local data manager's local checkpoint control file, it did not record information from the DIH block originating with the node that sent the signal as part of the data written. This meant that, later in start phase 9, when attempting to send a GCP_SAVECONF signal in response to the GCP_SAVEREQ, this information was not available, which meant the response could not be sent, resulting in an unplanned shutdown of the data node. (Bug #30187949) * Setting EnableRedoControl to false did not fully disable MaxDiskWriteSpeed, MaxDiskWriteSpeedOtherNodeRestart, and MaxDiskWriteSpeedOwnRestart as expected. (Bug #29943227) References: See also: Bug #31337487. * Removed a memory leak found in the ndb_import utility. (Bug #29820879) * A BLOB value is stored by NDB in multiple parts; when reading such a value, one read operation is executed per part. If a part is not found, the read fails with a row not found error, which indicates a corrupted BLOB, since a BLOB should never have any missing parts. A problem can arise because this error is reported as the overall result of the read operation, which means that mysqld sees no error and reports zero rows returned. This issue is fixed by adding a check specifically for the case in wich a blob part is not found. Now, when this occurs, overwriting the row not found error with corrupted blob, which causes the originating SELECT statement to fail as expected. Users of the NDB API should be aware that, despite this change, the NdbBlob::getValue() method continues to report the error as row not found in such cases. (Bug #28590428) * Incorrect handling of operations on replicas during node restarts could result in a forced shutdown, or in content diverging between replicas, when primary keys with nonbinary (case-sensitive) equality conditions were used. (Bug #98526, Bug #30884622) On Behalf of MySQL Release Engineering Team Piotr Obrzut [Less]

MySQL 8.0.21 is out, and the WARP storage engine has been updated to support the changes made in the new version. There are no significant functionality changes to the storage engine for MySQL 8.0.21, only the minor changes required to compile in ... [More] the new version.   I will be posting benchmarks of WARP vs InnoDB and Column Store using the Star Schema Benchmark, DBT3, and some other comparison tests. I will also be releasing a Docker image to make testing WARP easy.  As always, binaries are available upon request.  Keep in mind that WARP is a pluggable storage engine, and you can request just the plugin, or the whole MySQL 8 release,  for version 8.0.19, 8.0.20, or 8.0.21. [Less]

MySQL 8.0.21 has been released today, wooohooo \o/ As usual, this release contains contributions and let me thanks all the contributors on behalf of the MySQL Team. MySQL 8.0.21 includes contributions from Edgars Irmejs, Daniël van Eeden ... [More] , Jeremy Cole, Wenfeng Shih, Billy O’Neal, Lou Shuai, Tsubasa Tanaka and Facebook. Thank you all for your great contributions. MySQL is an Open Source project, GPL, and we accept contributions ! Here is the list of the contributions above: Filesort chosen where index should’ve been, using LIMIT, contribution by Edgars Irmejs Use mysql_config for –with-mysql-capi= when using –static, contribution by Daniël van Eeden Better error in comp_err with blank space only lines, contribution by Facebook, and some others… Dangerous optimization reconsidering_access_paths_for_index_ordering, contribution by Jeremy Cole Implement context manager, contribution by Wenfeng Shih Include missing headers breaking VS2019 version 16.6 nightly, contribution by Billy O’Neal mysql-connector-cpp cmake files not work well when as a third party, contribution by Lou Shuai a security contribution from Tsubasa Tanaka If you have patches and you also would like to be part of the MySQL Contributors, you can do so from MySQL’s GitHub repository (requires signing the Oracle Contributor Agreement). Thank you again for the contributions and see you for the next release ! [Less]

MySQL 8.0.21 was released today and one of the many new features is the JSON_VALUE() function. The main motivation is to ease index creation values from JSON data but there is more to it.JSON_VALUE() finds a specified scalar JSON value in JSON data ... [More] and returns it as a SQL value.Examples I will use the mysql_x example database data for examples.   So let us start with getting the life expectancy data.SELECT JSON_EXTRACT(doc, "$.demographics.LifeExpectancy") AS raw FROM countryinfo LIMIT 4;+--------------------+| raw                |+--------------------+| 78.4000015258789   || 45.900001525878906 || 38.29999923706055  || 76.0999984741211   |+--------------------+That is great information if not exactly human eye friendly.We can use JSON_VALUE() to make it a little easier for humansSELECT JSON_VALUE(doc, "$.demographics.LifeExpectancy" RETURNING DECIMAL(6,2)) AS trimmed FROM countryinfo LIMIT 4;+---------+| trimmed |+---------+|   78.40 ||   45.90 ||   38.30 ||   76.10 |+---------+And it can be very useful in a WHERE clause. In this example there is no RETURNING clause.SELECT doc->"$.Name" FROM countryinfo WHERE JSON_VALUE(doc, "$.demographics.LifeExpectancy"      RETURNING DECIMAL(6,3)) > 80.1;+---------------+| doc->"$.Name" |+---------------+| "Andorra"     || "Japan"       || "Macao"       || "San Marino"  |+---------------+The optional RETURN clause will cast your data as FLOAT, DOUBLE, DECIMAL, SIGNED,UNSIGNED, DATE, TIME, DATETIME, CHAR, or JSON.There are even on empty and on error clauses.SELECT JSON_VALUE('{firstname:"John"}', '$.lastname'                       DEFAULT 'No last name found' ON ERROR) AS "Last Name";+--------------------+| Last Name          |+--------------------+| No last name found |+--------------------+And of course it can be used to help define indexes.CREATE TABLE xdemo (j JSON, x INTEGER,   key((json_value(j, '$.id'))) );All opinions expressed in this blog are those of Dave Stokes who is actually amazed to find anyone else agreeing with him [Less]

     Recently the MySQL 8.0 Developer Certification became available joining the MySQL 8.0 Developer Certifications.  I have recently seen posts on various social media sites asking what is on the exam, is there an exam guide, and what do you 'really ... [More] need to know' to pass the exam.   Both tests are very tough.  Neither is going to be passed by rote memorization as many of the questions require analysis of system output before trying to adjust for the desired result.  There are no true or false questions and no essays.  What you will get is a series of questions written by subject matter experts that range from testing basic conceptual knowledge to very tough assessments of how to fix problems.  BTW the exam software lets you mark questions for later review and it does help to bypass the tougher questions for later review at the end of the test.  Are the question tricky?  No, not really.  They really require in depth knowledge of MySQL 8.0.  If you have ever interviewed someone for a DBA job you know there are certain points of knowledge (pain points) that a candidate MUST have to be trusted with your precious data.  Imagine going to your physician and having to identify which body part is a knee and which part is an elbow.  I personally would trust anyone with either the 8.0 DBA or 8.0 Developer certification to know their stuff.  Certification guide? Nope, sorry. Back in the 5.0 days there was a team effort to produce a comprehensive exam guide.  But 5.0 was a long time ago and there was an effort back in the 5.6 days for a resurrected guide that did not come to fruition. And having written a technical book, I can assure you that any such work is like writing in sand on a busy holiday vacation spot beach as the content is constantly changes and the community is adding or dropping tools continually.   I highly recommend Oracle's classes like MySQL For Developers and from regular reviews of the course materials on my part tell me that the curriculum team  does a fantastic job conveying the complex material way in an easy to consume package of literature and exercises.  I still recommend practicing the exercises for several weeks after the class before taking the exam.  Exam crams?  Do not waste you money.  The 'dumps' I have examined in the past are either poor third-hands recitations of poor interpretations of what was on a test or bad copies from the manual. How to Have a Good Chance to Pass the Exam   Review the exam topics below, using it as a check list.  Go to the MySQL Manual enter and read the sections for that area. Make sure you understand any examples and please do try them on your own scratch server.  Please write down notes in a notebook if you think having a consolidated review tool is handy for you.   Also check the MySQL Server Team blog and Planet.mysql.com for blogs from other Oracle MySQL Teams.  And if you have questions please ask away on forums.mysql.com and mysqlcommunity.slack,com.  I monitor the Certification board on the forums if you have questionsThe Exam Topics  DBA Certification  Architecture Configure client connections to the server Understand how MySQL stores data Understand how InnoDB stores data and logs Configure buffers and caches Understand and use the Data Dictionary Security Create user accounts and roles Use authentication plug-ins Control user and role permissions Recognize common security risks Secure MySQL server connections Provide password and login security Secure the MySQL host environment Prevent SQL injection attacks Encrypt MySQL data Configure MySQL Enterprise Firewall Query Optimization Examine how MySQL optimizes queries Analyze queries with MySQL Enterprise Monitor Create indexes to improve server performance Monitor and understand index statistics High Availability Techniques Explain how replication provides high availability and scalability Configure replication Explain the role of the binary log in replication Configure multisource replication Explain the role of replication threads Monitor and troubleshoot replication Describe MySQL InnoDB cluster and Group Replication Configure a MySQL InnoDB cluster Perform an InnoDB cluster recovery Developer Certification Connectors and APIs Choose between connectors for a given application Demonstrate connector use, management and configuration Retrieve data from the database by using a connector Handle special values Secure credentials and connections MySQL Schema Objects and Data Design, create, and alter views Store and process string data Store and process numeric data Store and process temporal data Store and process spatial data Query Optimization Use indexes for optimization Analyze queries for optimization Rewrite queries for optimization JSON and Document Store Create and store JSON documents Process data in JSON documents Explain application development with NoSQL and XDevAPI Create and access a document store Use MySQL Shell to access document stores Data-driven Applications Use prepared statements Set SQL Modes to change MySQL behavior Handle and interpret errors and warnings Display query results Aggregate and summarize data Advanced Report Generation Transactions Control transactions in SQL Control transactions in applications Resolve consistency problems with isolation levels Understand locking mechanisms within MySQL MySQL Stored Programs Create and execute stored routines Explain the programming constructs used in stored routines Create and execute triggers Schedule database operations Server Installation and Configuration Install and use the MySQL server and client programs Identify the files and folders created during installation Start and stop MySQL Upgrade MySQL Configure MySQL by using options and option files Configure MySQL variables Launch multiple MySQL servers on the same host Monitoring and Maintenance Configure and view MySQL log files Monitor MySQL processes and status Configure MySQL Enterprise Audit Use MySQL Enterprise Monitor to view activity in MySQL Monitor database growth and explain capacity planning Troubleshoot problems with locked resources Backups and Recovery Distinguish between the different types of backup Implement a backup strategy Backup and restore data with MySQL Enterprise Backup Use mysqldump and mysqlpump to perform logical backups Explain when and how to use raw file backups Back up the binary log All opinions expressed in this blog are those of Dave Stokes who is actually amazed to find anyone else agreeing with him [Less]

Dear MySQL users, MySQL Connector/J 8.0.21 is the latest General Availability release of the MySQL Connector/J 8.0 series. It is suitable for use with MySQL Server versions 8.0, 5.7, and 5.6. It supports the Java Database Connectivity (JDBC) ... [More] 4.2 API, and implements the X DevAPI. In the documentation for MySQL 8.0.21, we have started changing the term "master" to "source", the term "slave" to "replica", the term "whitelist" to "allowlist", and the term "blacklist" to "blocklist". There are currently no changes to the product's syntax, so these terms are still present in the documentation where the current code requires their use. See the blog post MySQL Terminology Updates (https://mysqlhighavailability.com/mysql-terminology-updates/) for more information. This release includes the following new features and changes, also described in more detail on https://dev.mysql.com/doc/relnotes/connector-j/8.0/en/news-8-0-21.html As always, we recommend that you check the "CHANGES" file in the download archive to be aware of changes in behavior that might affect your application. To download MySQL Connector/J 8.0.21 GA, see the "General Availability (GA) Releases" tab at http://dev.mysql.com/downloads/connector/j/ Enjoy! Changes in MySQL Connector/J 8.0.21 (2020-07-13, General Availability) * Functionality Added or Changed * Bugs Fixed Functionality Added or Changed * X DevAPI: The JSON Schema Validation Functions ( https://dev.mysql.com/doc/refman/8.0/en/json-validation-functions.html ) on MySQL servers are now supported by Connector/J; see Schema Validation for details. * The required versions of the 3rd-party libraries needed for running or compiling Connector/J have been changed; new requirements for additional libraries have also been added. See Installing Connector/J from a Binary Distribution ( https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-binary-installation.html ) and Installing from Source ( https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-installing-source.html ) for details. Bugs Fixed * When trying to set a parameter for a PreparedStatement using the method PreparedStatement.setObject(parameterIndex, "false", Types.BOOLEAN), the value was set to true instead of false. (Bug #30911870, Bug #98237) On Behalf of MySQL Release Engineering Team, Surabhi Bhat [Less]

Dear MySQL users, The MySQL developer tools team announces 8.0.21 as our General Availability (GA) for MySQL Workbench 8.0. For discussion, join the MySQL Workbench Forums: http://forums.mysql.com/index.php?152 The release is now available in ... [More] source and binary form for a number of platforms from our download pages at: http://dev.mysql.com/downloads/tools/workbench/ Enjoy! Changes in MySQL Workbench 8.0.21 (2020-07-13, General Availability) Functionality Added or Changed * A new check box was added to the dialog for resetting an expired password. When selected it indicates that the server version in use precedes MySQL 5.7. (Bug #30799058) * MySQL Workbench now supports the following MySQL 8.0.19 and 8.0.20 server language features: + DROP CHECK, ALTER CONSTRAINT, and DROP CONSTRAINT in ALTER TABLE statements. + Locking clause for query expressions. + Table values constructor. + Short table select syntax. + New requirements for the CHANGE MASTER replication statement (row format, primary key check). + Failed login attempts and password lock time in ALTER USER statements. + Format support for EXPLAIN ANALYZE statements. + New and changed keywords: o ARRAY o FAILED_LOGIN_ATTEMPTS o MASTER_COMPRESSION_ALGORITHM o MASTER_TLS_CIPHERSUITES o MASTER_ZSTD_COMPRESSION_LEVEL o MEMBER o OFF o PASSWORD_LOCK_TIME o PRIVILEGE_CHECKS_USER o RANDOM o REQUIRE_ROW_FORMAT o REQUIRE_TABLE_PRIMARY_KEY_CHECK o STREAM o TIMESTAMP o TIME Bugs Fixed * MySQL Workbench Migration Wizard encountered type -154 (SQL_SS_TIME2) while copying Microsoft SQL Server tables, and it returned an error on the unhandled type. This fix adds the following new SQL data types to the wizard: SQL_SS_TIME2 (supported by MySQL) and SQL_SS_TIMESTAMPOFFSET (not supported). (Bug #30884140) * The TableRead, TableInsert, TableUpdate, and TableDelete events for each table touched by a query did not include complete information in the Audit Inspector. (Bug #30807539) * Valid TABLE and VALUES statements were identified as having syntax errors in the SQL editor. (Bug #30775372, Bug #98266, Bug #30775008, Bug #98263) * MySQL accounts created during the prerequisite setup using the Create MEB Account button were not granted sufficient privilege to schedule an online backup or to execute a full backup on Windows. (Bug #30774786) * The Table Data Import Wizard returned an error when used to import a large JSON file, rather than loading the file. (Bug #30733445) * Text selected in the SQL editor was blocked by the highlight color. (Bug #30369329, Bug #97070) * A change made to the CREATE statement to rename an existing stored procedure did not revise the corresponding name in the generated DROP PROCEDURE statement when the change was applied using the editor. This fix modifies the generated statement to no longer drop the original stored procedure after it is renamed. (Bug #30103689, Bug #96289) * On Windows, statements that do not generate a result set, such as INSERT or UPDATE statements, caused MySQL Workbench to close unexpectedly after the EXPLAIN operation was executed and then the Result Grid output type was selected. (Bug #27576669, Bug #89745) * Although the installation and file path were valid, MySQL Workbench did not find the ogr2ogr and ogrinfo files when loading spatial data. (Bug #26447395, Bug #87074) * A column created with NULL ON UPDATE CURRENT_TIMESTAMP(6) prevented the MySQL Table Editor from showing table information, such as indexes, views, foreign keys, and so on. (Bug #26388250, Bug #86906) * Memory use on a Windows host was excessive when a large result set was exported to a file, causing MySQL Workbench to become unresponsive. (Bug #26139027, Bug #86430) * Synchronizing a database that included a table with JSON fields to the data model produced new, separate tables for the JSON data, instead of updating the original table. In this instance, the target MySQL version set in the modeling preference, 5.6.30 by default, does not support the operation. This fix sets the default version to MySQL 8.0, but the value can be adjusted by selecting Preferences, Modeling, and then MySQL from the Edit menu. (Bug #25788105, Bug #85648) * The zoom-out button did not alter the zoom level of spatial data when viewed from a Linux host, unless the zoom level was reset to the outermost level first. (Bug #25723313, Bug #85444) * MySQL Workbench became unresponsive for several minutes after a server startup attempt was made on macOS hosts. (Bug #25077227, Bug #83769) * No errors or warnings were reported when scheduling a backup with MySQL Enterprise Backup, although the backup did not execute as scheduled. (Bug #23562328, Bug #81788) * A Sybase database migration with the ODBC (FreeTDS) connection method produced an exception when the connection was tested. (Bug #23345282, Bug #81546) * MySQL Workbench server administration could not acquire management access to Oracle Solaris. For a list of supported platforms, visit https://www.mysql.com/support/supportedplatforms/workbench.html. (Bug #22453133, Bug #72204) * On Linux, edits made to values in the result grid were lost when using the pointer device to move within the grid, rather than pressing the Enter or Tab key to change the focus. (Bug #20742151, Bug #76387) * Forward engineering a valid MySQL Workbench model was unsuccessful when the operation was performed using a MySQL 5.5 server instance. (Bug #20637664) * On macOS, a query containing SELECT @@hostname returned the column header, but the query did not show any visible output unless the first row below the column header was selected. (Bug #20540937) * After reverting changes made to triggers in a schema that had been saved and synchronized, MySQL Workbench was not able to locate any differences when the reverted schema was re-synchronized with the model. (Bug #20222031) * A connection saved with MySQL Workbench Migration Wizard was no longer visible in the wizard after MySQL Workbench was upgraded to a later version. An attempt to save the connection again, using the same name, returned an error indicating that the original connection was preserved. (Bug #18454574) * No connection could be made to the PostgreSQL database system when it was selected as the source in MySQL Workbench Migration Wizard on macOS. (Bug #17299989) On Behalf of Oracle/MySQL Release Engineering Team, Nawaz Nazeer Ahamed [Less]

Dear MySQL users, MySQL Server 5.6.49, a new version of the popular Open Source Database Management System, has been released. MySQL 5.6.49 is recommended for use on production systems. For an overview of what's new in MySQL 5.6, please see ... [More] http://dev.mysql.com/doc/refman/5.6/en/mysql-nutshell.html Starting with 5.6.11, Microsoft Windows packages for MySQL 5.6 are available both as a "full" installer and as a "web" installer. The full installer is significantly larger and comes bundled with the latest software releases available. This bundle makes it easy to download and configure a full server and development suite. The web installer doesn't come bundled with any actual products and instead relies on download-on-demand to fetch only the products you choose to install. This makes the initial download much smaller but increases install time as the individual products will need to be downloaded. For information on installing MySQL 5.6.49 on new servers or upgrading to MySQL 5.6.49 from previous MySQL releases, please see http://dev.mysql.com/doc/refman/5.6/en/installing.html MySQL Server 5.6.49, is available in source and binary form for a number of platforms from our download pages at http://dev.mysql.com/downloads/mysql We welcome and appreciate your feedback, bug reports, bug fixes, patches, etc: http://bugs.mysql.com/report.php The following link lists the changes in the MySQL 5.6 since the release of MySQL 5.6.48. It may also be viewed online at http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-49.html ============================================================================== Changes in MySQL 5.6.49 (2020-07-13, General Availability) * Configuration Notes * Security Notes * Bugs Fixed Configuration Notes * tcmalloc is no longer a permitted value for the mysqld_safe --malloc-lib option. (Bug #31372027) Security Notes * The linked OpenSSL library for MySQL Server has been updated to version 1.1.1g. Issues fixed in the new OpenSSL version are described at https://www.openssl.org/news/cl111.txt and https://www.openssl.org/news/vulnerabilities.html. (Bug #31296697) Bugs Fixed * Partitioning: A query against a partitioned table, which used an ORDER BY, returned unordered results under the following conditions: + The table had a composite index with a prefix on one of the columns. + The query's WHERE clause contained an equality condition on the prefixed column. + The column with the prefix was the leftmost column in the index. + The column used in the ORDER BY was the rightmost column in the index. + The index was used for handling the ORDER BY. Our thanks to Quanan Han for the contribution. (Bug #84070, Bug #25207522) * Replication: When a replication source server shuts down and restarts, its MEMORY tables become empty. To replicate this effect to replicas, the first time that the source uses a given MEMORY table after startup, it notifies replicas that the table must be emptied by writing a DELETE statement for that table to the binary log. Previously, the generated DELETE statement was written to the binary log statement cache for the current session, which could result in it being logged together with other statements under the same GTID, or logged without BEGIN and COMMIT statements. Also, in some situations, the generated DELETE statement could consume the GTID intended for the transaction that triggered it. The generated DELETE statement is now logged with accompanying BEGIN and COMMIT statements, and the resulting transaction is flushed to the binary log immediately after it is written to the statement cache, so that it always receives its own GTID and is kept separate from other transactions. (Bug #30527929, Bug #25681518, Bug #77729) * Privileges on the INFORMATION_SCHEMA.FILES table were being checked incorrectly. (Bug #30350829) * mysql_store_result() could fail to detect invalid data packets. (Bug #29921423) * The server sometimes mistakenly removed a subquery with a GROUP BY when optimizing a query, even in some cases when this subquery was used by an outer select. This could occur when the subquery also used an aggregate function. (Bug #28240054) On behalf of the Release Engineering Team, Tvarita Jain [Less]