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BUG#26985561: BACKPORT BUG#26277771 TO 5.7 - BUG#27016053: REGRESSION IN BINLOG_LOG_ROW INTRODUCED BY ADD_PKE
This is backport of
Bug#26277771: BAD WRITE SET TRACKING WITH UNIQUE KEY ON A
DELETE FOLLOWED BY AN INSERT, which includes the optimizations
present on BUG#27016053: REGRESSION IN BINLOG_LOG_ROW INTRODUCED BY
ADD_PKE.
Issue:
======
The Writesets generated for keys were not using collation into consideration,
and because of that wrong last_committed and sequence_number were
getting added to binary log and thus transactions were getting applied
in wrong order by parallel applier on slave.
Solution:
=========
The fix uses make_sort_key to transform keys, with different charset and
collation, into its binary image, suitable for sorting using binary
comparison.
Optimizations:
==============
During detailed performance analysis it was discovered that there
were non-optimized memory allocations and memory copy operations on
the write-set extraction.
In order to solve the performance regression, the following actions
were made:
1) optimize memory allocation;
2) reduce memory copy operations;
3) only collect foreign key write-sets when them are not disabled;
4) do not collect and send duplicate write-sets through the network.
Note #### Sending passwords in plain text without SSL/TLS is extremely insecure.
4
+
Note #### Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information.
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