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| author | Marko Mäkelä <marko.makela@mariadb.com> | 2018-04-25 13:05:40 +0300 |
|---|---|---|
| committer | Marko Mäkelä <marko.makela@mariadb.com> | 2018-04-26 22:53:33 +0300 |
| commit | 76c62bc69c6f048111775877beb2072679b34ffb (patch) | |
| tree | 330a307d20c27caf63554f920647896799c96673 /storage/innobase/include/trx0rec.h | |
| parent | 83bd4dd1ee9e7abe2ee33860b15edf7ec72c6b14 (diff) | |
| download | mariadb-git-76c62bc69c6f048111775877beb2072679b34ffb.tar.gz | |
MDEV-15914: Restore MLOG_UNDO_INSERT
trx_undof_page_add_undo_rec_log(): Write the MLOG_UNDO_INSERT
record instead of the equivalent MLOG_2BYTES and MLOG_WRITE_STRING.
This essentially reverts commit 9ee8917dfd4b6c9d342cbc030ca71bad637fa24a.
In MariaDB 10.3, I attempted to simplify the crash recovery code
by making use of lower-level redo log records. It turns out that
we must keep the redo log parsing code in order to allow crash-upgrade
from older MariaDB versions (MDEV-14848).
Now, it further turns out that the InnoDB redo log record format is
suboptimal for logging multiple changes to a single page. This simple
change to the redo logging of undo log significantly affects the
INSERT and UPDATE performance.
Essentially, we wrote
(space_id,page_number,MLOG_2BYTES,2 bytes)
(space_id,page_number,MLOG_WRITE_STRING,N+4 bytes)
instead of the previously written
(space_id,page_number,MLOG_UNDO_INSERT,N+2 bytes)
The added redo log volume caused a single-threaded INSERT
(without innodb_adaptive_hash_index) of
1,000,000 rows to consume 11 seconds instead of 9 seconds,
and a subsequent UPDATE of 30,000,000 rows to consume 64 seconds
instead of 58 seconds. If we omitted all redo logging for the
undo log, the INSERT would consume only 4 seconds.
Diffstat (limited to 'storage/innobase/include/trx0rec.h')
| -rw-r--r-- | storage/innobase/include/trx0rec.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/storage/innobase/include/trx0rec.h b/storage/innobase/include/trx0rec.h index 955a726eb50..88c98625462 100644 --- a/storage/innobase/include/trx0rec.h +++ b/storage/innobase/include/trx0rec.h @@ -244,7 +244,7 @@ trx_undo_prev_version_build( into this function by purge thread or not. And if we read "after image" of undo log */ -/** Parse MLOG_UNDO_INSERT for crash-upgrade from MariaDB 10.2. +/** Parse MLOG_UNDO_INSERT. @param[in] ptr log record @param[in] end_ptr end of log record buffer @param[in,out] page page or NULL |