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  1. MariaDB Server
  2. MDEV-29593

Purge misses a chance to free not-yet-reused undo pages

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    Description

      While reviewing some code to prepare for MDEV-24402, I came across the following.

      In the case where the purge coordinator task invokes trx_purge_remove_log_hdr() outside of trx_purge_free_segment(), it would be possible to free the undo log page, provided that nothing was appended to the page after the purged records.

      Undo log pages may contain records for many unrelated transactions. If no "reuse of cached undo pages" took place, we could simply free the undo page. This could avoid some page writes and improve the performance of backup and recovery. It could also avoid unnecessary growth of the system tablespace or the temporary tablespace when they store undo log pages.

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          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33137 Assertion `end_lsn == page_lsn' failed in recv_recover_page

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed
          is blocked by

          Bug - A problem which impairs or prevents the functions of the product. MDEV-30671 innodb_undo_log_truncate=ON fails to wait for purge of transaction history

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-31382 SET GLOBAL innodb_undo_log_truncate=ON does not free space when no undo logs exist

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-21952 ibdata1 file size growing in MariaDB

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24402 CHECK TABLE may miss some cases of index inconsistencies

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-26782 InnoDB temporary tablespace: reclaiming of free space does not work

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-29401 InnoDB history list length increased in 10.6 compared to 10.5 for the same load

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

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              marko Marko Mäkelä
              marko Marko Mäkelä
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                Updated:
                Resolved:

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