Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-6191

row_search_for_mysql comment and code consistency about isolation level and gap locks

    XMLWordPrintable

Details

    • Bug
    • Status: Closed (View Workflow)
    • Minor
    • Resolution: Fixed
    • 5.5.37
    • 5.5.39
    • None
    • None

    Description

      mariadb-5.5/storage/xtradb/row/row0sel.c line 4137

          if (set_also_gap_locks
              && !(srv_locks_unsafe_for_binlog
             || trx->isolation_level <= TRX_ISO_READ_COMMITTED)
              && prebuilt->select_lock_type != LOCK_NONE) {
       
            /* Try to place a lock on the index record */
       
            /* If innodb_locks_unsafe_for_binlog option is used
            or this session is using a READ COMMITTED isolation
            level we do not lock gaps. Supremum record is really
            a gap and therefore we do not set locks there. */

      I was getting really confused about the comment and its relation to the code and I've come to the conclusion that the comment should say "this session is not using a REPEATABLE READ" and perhaps the condition could be isolation_level < TRX_ISO_REPEATABLE_READ to match.

      Of course I've looked at this too long and just may be wrong.

      Attachments

        Activity

          People

            jplindst Jan Lindström (Inactive)
            danblack Daniel Black
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:

              Git Integration

                Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.