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  1. MariaDB Server
  2. MDEV-26589

Assertion failure upon DECODE_HISTOGRAM with NULLs in first column

Details

    • Bug
    • Status: Closed (View Workflow)
    • Blocker
    • Resolution: Fixed
    • N/A
    • 10.7.1
    • Optimizer
    • None

    Description

      CREATE TABLE t1 (a INT, b INT);
      		 
      INSERT INTO t1 VALUES (NULL,1), (NULL,2);
      		 
      SET histogram_type = JSON_HB;
      		 
      ANALYZE TABLE t1 PERSISTENT FOR ALL;
      		 
      SELECT DECODE_HISTOGRAM(hist_type, histogram) from mysql.column_stats;
      		 
       
      		 
      # Cleanup
      		 
      DROP TABLE t1;

      preview-10.7-MDEV-21130-json-histograms 8fc778f3e9c

      		 
      mariadbd: /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_type.cc:7457: bool Type_handler::Item_send_str(Item*, Protocol*, st_value*) const: Assertion `!it
      		 
      em->null_value' failed.
      		 
      210911 12:44:49 [ERROR] mysqld got signal 6 ;
      		 
       
      		 
      #7  0x00007fcbe9582f36 in __GI___assert_fail (assertion=0x5595b90af58f "!item->null_value", file=0x5595b90ac490 "/data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_type.cc", line=7457, function=0x5595b90af5a8 "bool Type_handler::Item_send_str(Item*, Protocol*, st_value*) const") at assert.c:101
      		 
      #8  0x00005595b7c7dcc9 in Type_handler::Item_send_str (this=0x5595ba6f9ac0 <type_handler_long_blob>, item=0x7fcbc8015a90, protocol=0x7fcbc80013a0, buf=0x7fcbe45ddc60) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_type.cc:7457
      		 
      #9  0x00005595b7ad0358 in Type_handler_string_result::Item_send (this=0x5595ba6f9ac0 <type_handler_long_blob>, item=0x7fcbc8015a90, protocol=0x7fcbc80013a0, buf=0x7fcbe45ddc60) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_type.h:5440
      		 
      #10 0x00005595b74ca666 in Item::send (this=0x7fcbc8015a90, protocol=0x7fcbc80013a0, buffer=0x7fcbe45ddc60) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/item.h:1227
      		 
      #11 0x00005595b754fe9e in Protocol::send_result_set_row (this=0x7fcbc80013a0, row_items=0x7fcbc8015618) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/protocol.cc:1327
      		 
      #12 0x00005595b76b6e27 in select_send::send_data (this=0x7fcbc8016bd0, items=...) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_class.cc:3072
      		 
      #13 0x00005595b7914c19 in select_result_sink::send_data_with_check (this=0x7fcbc8016bd0, items=..., u=0x7fcbc8005120, sent=1) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_class.h:5634
      		 
      #14 0x00005595b78e34fa in end_send (join=0x7fcbc8016bf8, join_tab=0x7fcbc8018278, end_of_records=false) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:22285
      		 
      #15 0x00005595b78de5b1 in evaluate_join_record (join=0x7fcbc8016bf8, join_tab=0x7fcbc8017ec8, error=0) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:21278
      		 
      #16 0x00005595b78dda54 in sub_select (join=0x7fcbc8016bf8, join_tab=0x7fcbc8017ec8, end_of_records=false) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:21094
      		 
      #17 0x00005595b78dbe49 in do_select (join=0x7fcbc8016bf8, procedure=0x0) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:20602
      		 
      #18 0x00005595b788b47c in JOIN::exec_inner (this=0x7fcbc8016bf8) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:4735
      		 
      #19 0x00005595b78897a5 in JOIN::exec (this=0x7fcbc8016bf8) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:4513
      		 
      #20 0x00005595b788c97b in mysql_select (thd=0x7fcbc8000db8, tables=0x7fcbc8015c10, fields=..., conds=0x0, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147748608, result=0x7fcbc8016bd0, unit=0x7fcbc8005120, select_lex=0x7fcbc8015378) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:4991
      		 
      #21 0x00005595b786cbb8 in handle_select (thd=0x7fcbc8000db8, lex=0x7fcbc8005058, result=0x7fcbc8016bd0, setup_tables_done_option=0) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_select.cc:545
      		 
      #22 0x00005595b77c7176 in execute_sqlcom_select (thd=0x7fcbc8000db8, all_tables=0x7fcbc8015c10) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_parse.cc:6256
      		 
      #23 0x00005595b77b342a in mysql_execute_command (thd=0x7fcbc8000db8, is_called_from_prepared_stmt=false) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_parse.cc:3946
      		 
      #24 0x00005595b77d086c in mysql_parse (thd=0x7fcbc8000db8, rawbuf=0x7fcbc8015290 "SELECT DECODE_HISTOGRAM(hist_type, histogram) from mysql.column_stats", length=69, parser_state=0x7fcbe45df480) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_parse.cc:8030
      		 
      #25 0x00005595b77a6b0c in dispatch_command (command=COM_QUERY, thd=0x7fcbc8000db8, packet=0x7fcbc800b849 "", packet_length=69, blocking=true) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_parse.cc:1896
      		 
      #26 0x00005595b77a3ba2 in do_command (thd=0x7fcbc8000db8, blocking=true) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_parse.cc:1404
      		 
      #27 0x00005595b7b0d493 in do_handle_one_connection (connect=0x5595bc8dd8c8, put_in_cache=true) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_connect.cc:1418
      		 
      #28 0x00005595b7b0cc5b in handle_one_connection (arg=0x5595bc8dc1f8) at /data/src/preview-10.7-MDEV-21130-json-histograms/sql/sql_connect.cc:1312
      		 
      #29 0x00005595b83eea83 in pfs_spawn_thread (arg=0x5595bc8dd418) at /data/src/preview-10.7-MDEV-21130-json-histograms/storage/perfschema/pfs.cc:2201
      		 
      #30 0x00007fcbe9a9b609 in start_thread (arg=<optimized out>) at pthread_create.c:477
      		 
      #31 0x00007fcbe966e293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

      Reproducible with at least MyISAM and InnoDB.

      As far as I could tell, the important part here is that the first column of the table has only NULLs. If one of the values in the first column isn't NULL, the failure doesn't happen.
      If this generalization is incorrect, please modify the ticket summary to avoid confusion.

      Attachments

        Issue Links

          relates to

          Task - A task that needs to be done. MDEV-21130 Histograms: use JSON as on-disk format

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

          Activity

            Ascending order - Click to sort in descending order
            psergei Sergei Petrunia added a comment -

            Not reproducible in bb-10.7-mdev26519 branch, revision 0fe2cfd45e616e93d47aa9e224db468f32dd391a

            psergei Sergei Petrunia added a comment - Not reproducible in bb-10.7-mdev26519 branch, revision 0fe2cfd45e616e93d47aa9e224db468f32dd391a
            psergei Sergei Petrunia added a comment -

            Wait, it was repeatable. Now fixed.

            psergei Sergei Petrunia added a comment - Wait, it was repeatable. Now fixed.
            psergei Sergei Petrunia added a comment -

            Fixed in preview-10.7-MDEV-26519-improved-json-histograms tree.

            psergei Sergei Petrunia added a comment - Fixed in preview-10.7- MDEV-26519 -improved-json-histograms tree.
            elenst Elena Stepanova added a comment - - edited

            It is not fixed in preview-10.7-MDEV-26519-json-histograms. Same test case still fails same way.
            Maybe the fix got lost somewhere between the trees (the previous comment mentions a different branch).

            elenst Elena Stepanova added a comment - - edited It is not fixed in preview-10.7- MDEV-26519 -json-histograms. Same test case still fails same way. Maybe the fix got lost somewhere between the trees (the previous comment mentions a different branch).
            psergei Sergei Petrunia added a comment -

            Indeed, the fix was pushed into the wrong branch.

            I've now cherry-picked it into the right branch:

            commit 7b49fb5803e4589d4bab2123813784d9ff29018d
            		 
            Author: Sergei Petrunia <psergey@askmonty.org>
            		 
            Date:   Fri Oct 1 14:24:41 2021 +0300
            		 
             
            		 
                MDEV-26589: Assertion failure upon DECODE_HISTOGRAM with NULLs
            		 
                
                Item_func_decode_histogram::val_str should correctly set null_value
            		 
                when "decoding" JSON histogram.

            psergei Sergei Petrunia added a comment - Indeed, the fix was pushed into the wrong branch. I've now cherry-picked it into the right branch: commit 7b49fb5803e4589d4bab2123813784d9ff29018d Author: Sergei Petrunia <psergey@askmonty.org> Date: Fri Oct 1 14:24:41 2021 +0300   MDEV-26589: Assertion failure upon DECODE_HISTOGRAM with NULLs Item_func_decode_histogram::val_str should correctly set null_value when "decoding" JSON histogram.

            People

              psergei Sergei Petrunia
              elenst Elena Stepanova
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                Updated:
                Resolved:

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