Month: May 2018

3 Great Reasons to Learn the Latest in Oracle Database Technology

Want to learn more about the benefits of Oracle Database 12c R2? Why should you care? Here’s 3 great reasons:


1. Oracle Database 12c R2 is Oracle’s Pre-Cloud environment platform.   

Oracle Database Cloud service is a highly optimized (storage, memory, management) container database using multitenant architecture. You can configure Oracle Database 12c R2 in your On-Premises environment and when ready, migrate to the cloud.

2.  Solve the compute, memory and storage customer issues.

Even if you’re not ready to transfer everything over to the Cloud, upgrading to Oracle Database 12c R2 allows DBAs to fully take advantage of the latest technology advancements and enhancements of multitenant architecture, and other database features including; high availability, data protection, backup and recovery, consolidation and redundancy.  

3.  Utilize enhanced functionality and capabilities.

Prior to Oracle Database 12c, multitenant architecture wasn’t available.  Now with 12c R2 and multitenant container databases, portablity is far easier.

Test Your Oracle Database 12c R2 Skills

Take this FREE Oracle Database 12c R2 Quiz and find out where you stand. 

Our learning and certification paths teach you about the latest in database technology, and how to prepare and be ready for any future migration to the cloud. We have training, practice tests from our authorized provider Kaplan IT Training and new certifications available.
Ramp up learning 12c R2 with these links:


Percona Server for MySQL 5.7.22-22 Is Now Available

Percona Server for MySQL

Percona announces the GA release of Percona Server for MySQL 5.7.22-22 on on May 31, 2018. Download the latest version from the Percona web site or the Percona Software Repositories. You can also run Docker containers from the images in the Docker Hub repository. Based on MySQL 5.7.22, including all the bug fixes in it, Percona Server for […]

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Don’t Drown in your Data Lake

Don't drown in your data lake

A data lake is “…a method of storing data within a system or repository, in its natural format, that facilitates the collocation of data in various schemata and structural forms…”1. Many companies find value in using a data lake but aren’t clear that they need to properly plan for it and maintain it in order […]

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MongoDB: deploy a replica set with transport encryption (part 3/3)

MongoDB Encryption Replica Sets

In this third and final post of the series, we look at how to configure transport encryption on a deployed MongoDB replica set. Security vulnerabilities can arise when internal personnel have legitimate access to the private network, but should not have access to the data. Encrypting intra-node traffic ensures that no one can “sniff” sensitive data […]

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ALTER TABLE Improvements in MariaDB Server 10.3

ALTER TABLE Improvements in MariaDB Server 10.3
Marko Mäkelä

Thu, 05/31/2018 – 08:10

MariaDB Server 10.3.7 (the first Generally Available release in the series) includes some ALTER TABLE improvements that are worth mentioning. Last October, I wrote about the Instant ADD COLUMN feature that was introduced in the 10.3.2 alpha release. The effort to support instant ALTER TABLE in MariaDB comes from a collaboration with ServiceNow. The first part of that, instant ADD COLUMN, was brainstormed in April 2017 by engineers from MariaDB Corporation, Alibaba and Tencent. A prototype was first developed by Vin Chen (陈福荣) from the Tencent Game DBA Team and was later refined by our team for the MariaDB version.

Part of the original plan was to introduce syntax for ALTER TABLE…ALGORITHM=INSTANT in order to be able to give a guarantee that the requested operation will be performed instantly, or not at all. This was finally implemented in MariaDB Server 10.3.7. We also introduced the keyword ALGORITHM=NOCOPY, which will refuse an operation if the table would be rebuilt.


INSERT INTO t(id,u) VALUES(1,1),(2,2),(3,3);

SET alter_algorithm=instant;
# There is no instant DROP COLUMN yet
SET alter_algorithm=default;

The example illustrates a new configuration parameter alter_algorithm. A DBA could set it globally in the MariaDB Server configuration to NOCOPY in order to prevent expensive ALTER TABLE statements from being executed by mistake.

The ALGORITHM=INPLACE syntax, which was added in MariaDB Server 10.0, can misleadingly suggest that no copying ever takes place. However, until the efforts to implement instant schema changes (instant DROP COLUMN and others being worked on for upcoming MariaDB Server releases), the inplace operation often did involve copying, potentially allocating quite a bit of extra space, not only for the new copy of the table, but also for pre-sorting the data and for logging concurrent modifications to the table (ALTER ONLINE TABLE). With the ALGORITHM=INSTANT and ALGORITHM=NOCOPY clauses, which represent proper subsets of ALGORITHM=INPLACE, will are clarifying the situation.

Imitation is the sincerest form of flattery

We’re happy to hear that MySQL 8.0 will add support for instant ADD COLUMN that is based on our work. But you don’t have to wait to try it.

Try it out

MariaDB Server 10.3.7 was announced as GA on May 25, 2018. Download MariaDB TX 3.0, which includes MariaDB Server 10.3.7 to upgrade your current server and immediately get the benefit of instant ADD COLUMN for your old InnoDB tables.

Note that if you need to export InnoDB data files to older servers than MariaDB Server 10.3, you must rebuild the table first: ALTER TABLE t FORCE;

Big Data
MariaDB Releases

Perhaps the most user-visible InnoDB changes in the MariaDB Server 10.3.7 GA release are Instant ADD COLUMN for InnoDB tables, the new parameter alter_algorithm and the clauses ALGORITHM=INSTANT and ALGORITHM=NOCOPY that can protect the database from executing costly ALTER TABLE operations taking hours.

Upgrade to MariaDB Server 10.3.7, and enjoy the instant ADD COLUMN with your old InnoDB data files.

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Percona Server for MySQL 5.6.40-84.0 Is Now Available

Percona announces the release of Percona Server for MySQL 5.6.40-84.0 on May 30, 2018 (downloads are available here and from the Percona Software Repositories). Based on MySQL 5.6.40, including all the bug fixes in it, Percona Server for MySQL 5.6.40-84.0 is now the current GA release in the 5.6 series. All of Percona’s software is open-source and free.
New Features

A new string variable version_suffix allows to change suffix for the Percona Server version string returned by the read-only version variable. This allows to append the version number for the server with a custom suffix to reflect some build or configuration specifics. Also version_comment (default value of which is taken from the CMake COMPILATION_COMMENT option) is converted from a global read-only to a global read-write variable and thereby it is now cutomizable.
Query response time plugin now can be disabled at session level with use of a new variable query_response_time_session_stats.

Bugs Fixed

Compilation warning was fixed for -DWITH_QUERY_RESPONSE_TIME=ON CMake compilation option, which makes QRT to be linked statically. Bug fixed #3841.
A code clean-up was done to fix clang 6 specific compilation warnings and errors (bug fixed #3893, upstream #90111).
Using -DWITHOUT_<PLUGIN>=ON CMake variable to exclude a plugin from the build didn’t work for some plugins, including a number of storage engines. Bug fixed #3901.
A clean-up in Percona Server binlog-related code was made to avoid uninitialized memory comparison. Bug fixed #3925 (upstream #90238).
Temporary file I/O was not instrumented for Performance Schema. Bug fixed  #3937  (upstream  #90264).
A key_block_size value was set automatically by the Improved MEMORY Storage Engine, which resulted in warnings when changing the engine type to InnoDB, and constantly growing key_block_size during alter operations. Bugs fixed #3936, #3940, and #3943.
Percona Server Debian packages description included reference to /etc/mysql/my.cnf file, which is not actually present in these packages. Bug fixed #2046.
Fixes were introduced to remove GCC 8 compilation warnings for the Percona Server build, retaining compatibility with old compiler versions, including GCC 4.4. Bugs fixed #3950 and #4471.
A typo in plugin.cmake file prevented to compile plugins statically into the server. Bug fixed #3871 (upstream #89766).
-DWITH_NUMA=ON build option was silently ignored by CMake when NUMA development package was not installed, instead of exiting by error. Bug fixed #4487.
Variables innodb_buffer_pool_populate and numa_interleave mapped to the upstream innodb_numa_interleave variable in 5.6.27-75.0 were reverted to their original implementation due to upstream variant being less effective in memory allocation. Now buffer pool is allocated with MAP_POPULATE, forcing NUMA interleaved allocation at the buffer pool initialization time. Bug fixed #3967.
audit_log_include_accounts variable did not take effect if placed in my.cnf configuration file, while still working as intended if set dynamically. Bug fixed #3867.
Synchronization between between innodb_kill_idle_transaction and kill_idle_transaction system variables was broken because of the regression in Percona Server 5.6.40-83.2. Bug fixed #3955.
Executing the SHOW GLOBAL STATUS expression could cause “data drift” on global status variables in case of a query rollback: the variable, being by its nature a counter and allowing only an increase, could return to its previous value. Bug fixed #3951 (upstream #90351).
ALTER TABLE … COMMENT = … statement caused TokuDB to rebuild the whole table, which is not needed, as only FRM metadata should be changed. The fix was provided as a contribution by Fungo Wang. Bugs fixed #4280 and #4292.
A number of Percona Server 8.0 TokuDB fixes have been backported to Percona Server 5.6 in preparation for using MySQL 8.0. Bugs fixed  #4379,  #4380,  #4387,  #4378,  #4383,  #4384,  #4386,  #4382, #4391, #4390, #4392, and #4381.

TokuDB Changes and Fixes

Two new variables, tokudb_enable_fast_update and tokudb_enable_fast_upsert, were introduced to facilitate the TokuDB fast updates feature, which involves queries optimization to avoid random reads during their execution. Bug fixed #4365.
A data race was fixed in minicron utility of the PerconaFT, as a contribution by Rik Prohaska. Bug fixed #4281.
Row count and cardinality decrease to zero took place after long-running REPLACE load, ending up with full table scans for any action.

Other Bugs Fixed

#3818 “Orphaned file mysql-test/suite/innodb/r/percona_innodb_kill_idle_trx.result”

#3926 “Potentially truncated bitmap file name in log_online_open_bitmap_file_read_only() (storage/innobase/log/”

#2204 “Test main.audit_log_default_db is unstable”

#3767 “Fix compilation warnings/errors with clang”

#3773 “Incorrect key file for table frequently for tokudb”

#3794 “MTR test main.percona_show_temp_tables_stress does not wait for events to start”

#3798 “MTR test innodb.percona_extended_innodb_status fails if InnoDB status contains unquoted special characters”

#3887 “TokuDB does not compile with -DWITH_PERFSCHEMA_STORAGE_ENGINE=OFF”

#4388 “5.7 code still has TOKU_INCLUDE_OPTION_STRUCTS which is a MariaDB specific construct”

#4265 “TDB-114 (Change use of MySQL HASH to unordered_map) introduces memory leak”

#4277 “memory leaks in TDB-2 and TDB-89 tests”

#4276 “Data race on cache table attributes detected by the thread sanitizer”

#4451 “Implement better compression algo testing”

#4469 “variable use out of scope bug in get_last_key test detected by ASAN in clang 6”

#4470 “the cachetable-simple-pin-nonblocking-cheap test occasionally fails due to a locking conflict with the cachetable evictor”

#1131 “User_var_log_event::User_var_log_event(const char*, uint, const Format_description_log_event*): Assertion `(bytes_read == (data_written – ((old_pre_checksum_fd || (description_event->checksum_alg == BINLOG_CHECKSUM_ALG_OFF)) ? 0 : 4))) || ((“.

Find the release notes for Percona Server for MySQL 5.6.40-84.0 in our online documentation. Report bugs in the Jira bug tracker.
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