Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-9954

Prevent MEMORY tables from consuming all RAM

    XMLWordPrintable

    Details

      Description

      While the size of a single MEMORY/HEAP table is limited by max_heap_table_size there is no limit for the number of tables (max_tmp_table variable exists, but has no function and is deprecated) or for the total amount of RAM available for MEMORY tables.

      Memory usage of implicit memory tables is more or less limited by MIN(tmp_table_size, max_heap_table_size)*max_connections (when not taking subqueries and stored function calls into account), but so far nothing prevents a single user session from explicitly creating MEMORY tables until the mysqld process runs into an out-of-memory (OOM) situation ... which could e.g. be used for denial-of-service attacks ...

        Attachments

          Issue Links

            Activity

              People

              Assignee:
              Unassigned Unassigned
              Reporter:
              hholzgra Hartmut Holzgraefe
              Votes:
              1 Vote for this issue
              Watchers:
              3 Start watching this issue

                Dates

                Created:
                Updated:

                  Git Integration