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author | Alexander Barkov <bar@mariadb.com> | 2018-06-27 12:53:49 +0400 |
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committer | Alexander Barkov <bar@mariadb.com> | 2018-06-27 12:54:05 +0400 |
commit | 56145be2951e0085848187bf6df8a0269e53fc7a (patch) | |
tree | 582b1092ea07e717be7a89566fe5abca5833a746 /sql/sp_head.h | |
parent | 1d6bc0f01f58cacc1d31975eb5579a197f451a41 (diff) | |
download | mariadb-git-56145be2951e0085848187bf6df8a0269e53fc7a.tar.gz |
MDEV-16584 SP with a cursor inside a loop wastes THD memory aggressively
Problem:
push_cursor() created sp_cursor instances on THD::main_mem_root,
which is freed only after the SP instructions loop.
Changes:
- Moving sp_cursor declaration from sp_rcontext.h to sql_class.h
- Deriving sp_instr_cpush from sp_cursor. So now sp_cursor is created
only once (at the SP parse time) and then reused on all loop iterations
- Adding a new method reset() into sp_cursor (and its parent classes)
to reset an sp_cursor instance before reuse.
- Moving former sp_cursor members m_fetch_count, m_row_count, m_found
into a separate class sp_cursor_statistics. This helps to reuse
the code in sp_cursor constructors, and in sp_cursor::reset()
- Adding a helper method sp_rcontext::pop_cursor().
- Adding "THD*" parameter to so_rcontext::pop_cursors() and pop_all_cursors()
- Removing "new" and "delete" from sp_rcontext::push_cursor() and
sp_rconext::pop_cursor().
- Fixing sp_cursor not to derive from Sql_alloc, as it's now allocated
only as a part of sp_instr_cpush (and not allocated separately).
- Moving lex_keeper->disable_query_cache() from sp_cursor::sp_cursor()
to sp_instr_cpush::execute().
- Adding tests
Diffstat (limited to 'sql/sp_head.h')
-rw-r--r-- | sql/sp_head.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sql/sp_head.h b/sql/sp_head.h index dcea4191cde..580859b8831 100644 --- a/sql/sp_head.h +++ b/sql/sp_head.h @@ -1757,7 +1757,8 @@ private: /** This is DECLARE CURSOR */ -class sp_instr_cpush : public sp_instr +class sp_instr_cpush : public sp_instr, + public sp_cursor { sp_instr_cpush(const sp_instr_cpush &); /**< Prevent use of these */ void operator=(sp_instr_cpush &); |