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  1. MariaDB Server
  2. MDEV-3546

LP:715034 - Item_sum_distinct::clear(): Assertion `tree != 0' failed in maria-5.3-mwl89

        Details

        • Type: Bug
        • Status: Closed
        • Resolution: Fixed
        • Affects Version/s: None
        • Fix Version/s: None
        • Component/s: None
        • Labels:

          Description

          not reproducible in maria-5.3

          mysqld: item_sum.cc:1053: virtual void Item_sum_distinct::clear(): Assertion `tree != 0' failed.

          #8 0x006b0d98 in __assert_fail () from /lib/libc.so.6
          #9 0x081de625 in Item_sum_distinct::clear (this=0xae72f870) at item_sum.cc:1053
          #10 0x08308c64 in JOIN::reinit (this=0xae76e588) at sql_select.cc:1757
          #11 0x0830b830 in mysql_select (thd=0xae97c58, rref_pointer_array=0xae72f72c, tables=0xae749788, wild_num=0, fields=..., conds=0x0, og_num=0, order=0x0,
          group=0x0, having=0x0, proc_param=0x0, select_options=2147764741, result=0xae74a270, unit=0xae749480, select_lex=0xae72f628) at sql_select.cc:2616
          #12 0x08332f4a in mysql_explain_union (thd=0xae97c58, unit=0xae749480, result=0xae74a270) at sql_select.cc:19315
          #13 0x08332c4d in select_describe (join=0xae764070, need_tmp_table=false, need_order=false, distinct=false,
          message=0x88ad73c "Impossible WHERE noticed after reading const tables") at sql_select.cc:19275
          #14 0x0831a5ad in return_zero_rows (join=0xae764070, result=0xae74a270, tables=0xae72e808, fields=..., send_row=false, select_options=2147764740,
          info=0x88ad73c "Impossible WHERE noticed after reading const tables", having=0x0) at sql_select.cc:8718
          #15 0x083094f6 in JOIN::exec (this=0xae764070) at sql_select.cc:1917
          #16 0x0830bad1 in mysql_select (thd=0xae97c58, rref_pointer_array=0xae996f4, tables=0xae72e808, wild_num=1, fields=..., conds=0xae749a90, og_num=0,
          order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147764740, result=0xae74a270, unit=0xae99354, select_lex=0xae995f0)
          at sql_select.cc:2667
          #17 0x08332f4a in mysql_explain_union (thd=0xae97c58, unit=0xae99354, result=0xae74a270) at sql_select.cc:19315
          #18 0x082a1e6e in execute_sqlcom_select (thd=0xae97c58, all_tables=0xae72e808) at sql_parse.cc:5049
          #19 0x08298ffb in mysql_execute_command (thd=0xae97c58) at sql_parse.cc:2234
          #20 0x082a4584 in mysql_parse (thd=0xae97c58,
          rawbuf=0xae72d9f8 "EXPLAIN\nSELECT *\nFROM ( SELECT * FROM t2 ) AS a2\nJOIN t1 ON t1.f3\nWHERE t1.f11 IN ( SELECT 'd' )\nAND (SELECT DISTINCT SUM( DISTINCT f3 ) FROM t1)", length=146, found_semicolon=0xae8ff228) at sql_parse.cc:6077
          #21 0x08296c93 in dispatch_command (command=COM_QUERY, thd=0xae97c58, packet=0xaeafd49 "", packet_length=147) at sql_parse.cc:1210
          #22 0x08296140 in do_command (thd=0xae97c58) at sql_parse.cc:903
          #23 0x0829321e in handle_one_connection (arg=0xae97c58) at sql_connect.cc:1154
          #24 0x00821919 in start_thread () from /lib/libpthread.so.0
          #25 0x0076acce in clone () from /lib/libc.so.6

          revision-id: <email address hidden>
          date: 2011-02-03 17:00:28 +0200
          build-date: 2011-02-08 09:35:02 +0200
          revno: 2883
          branch-nick: maria-5.3-mwl89

          test case:

          CREATE TABLE t2 ( f2 int(11)) ;

          CREATE TABLE t1 ( f3 int(11), f11 varchar(1), KEY (f3)) ;
          INSERT INTO t1 VALUES ('6','m'),('4','c');

          EXPLAIN
          SELECT *
          FROM ( SELECT * FROM t2 ) AS a2
          JOIN t1 ON t1.f3
          WHERE t1.f11 IN ( SELECT 'd' )
          AND (SELECT DISTINCT SUM( DISTINCT f3 ) FROM t1) ;

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                timour Timour Katchaounov added a comment -

                Re: Item_sum_distinct::clear(): Assertion `tree != 0' failed in maria-5.3-mwl89
                Slightly simplified version of the test query:

                EXPLAIN
                SELECT *
                FROM ( SELECT * FROM t2 ) AS a2
                WHERE (SELECT distinct SUM(distinct f3 ) FROM t1);

                Show
                timour Timour Katchaounov added a comment - Re: Item_sum_distinct::clear(): Assertion `tree != 0' failed in maria-5.3-mwl89 Slightly simplified version of the test query: EXPLAIN SELECT * FROM ( SELECT * FROM t2 ) AS a2 WHERE (SELECT distinct SUM(distinct f3 ) FROM t1);
                Hide
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                timour Timour Katchaounov added a comment -

                Re: Item_sum_distinct::clear(): Assertion `tree != 0' failed in maria-5.3-mwl89
                Analysis:

                The failed assert is a result of calling Item_sum_distinct::clear() on an
                incomplete object for which Item_sum_distinct::setup() was not yet
                called.

                The reason is that JOIN::exec for the outer query calls JOIN::reinit()
                for all its subqueries, which in turn calls clear() for all aggregate functions
                of the subqueries. The call stack is:
                JOIN::reinit
                mysql_select
                mysql_explain_union
                select_describe
                JOIN::exec
                mysql_select
                mysql_explain_union

                This assert doesn't fail in the main 5.3 because constant subqueries
                are being executed during the optimize phase of the outer query,
                thus the Unique object is created before calling JOIN::exec for the
                outer query, and Item_sum_distinct::clear() actually cleans the
                Unique object.

                Solution:
                The best solution is the obvious one - aubstitute the assert with
                a test whether Item_sum_distinct::tree is NULL.

                Show
                timour Timour Katchaounov added a comment - Re: Item_sum_distinct::clear(): Assertion `tree != 0' failed in maria-5.3-mwl89 Analysis: The failed assert is a result of calling Item_sum_distinct::clear() on an incomplete object for which Item_sum_distinct::setup() was not yet called. The reason is that JOIN::exec for the outer query calls JOIN::reinit() for all its subqueries, which in turn calls clear() for all aggregate functions of the subqueries. The call stack is: JOIN::reinit mysql_select mysql_explain_union select_describe JOIN::exec mysql_select mysql_explain_union This assert doesn't fail in the main 5.3 because constant subqueries are being executed during the optimize phase of the outer query, thus the Unique object is created before calling JOIN::exec for the outer query, and Item_sum_distinct::clear() actually cleans the Unique object. Solution: The best solution is the obvious one - aubstitute the assert with a test whether Item_sum_distinct::tree is NULL.
                Hide
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                ratzpo Rasmus Johansson added a comment -

                Launchpad bug id: 715034

                Show
                ratzpo Rasmus Johansson added a comment - Launchpad bug id: 715034

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                  • Assignee:
                    timour Timour Katchaounov
                    Reporter:
                    philipstoev Philip Stoev
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                      Updated:
                      Resolved: