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  1. MariaDB Server
  2. MDEV-6954

SET STATEMENT rand_seedX = ...FOR ... makes the next rand() to return 0

        Details

        • Type: Bug
        • Status: Closed
        • Priority: Minor
        • Resolution: Fixed
        • Affects Version/s: 10.1.3
        • Fix Version/s: 10.1.4
        • Component/s: Admin statements
        • Labels:
          None

          Description

          Values of rand_seed1 and rand_seed2 can be set, but cannot be seen – server always shows fake zeros for them.
          However, after executing SET STATEMENT rand_seed..., the values are set to actual zeros, and the next rand() returns 0. It should not happen.

          MariaDB [test]> set statement rand_seed1=1, rand_seed2=1 for select 1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

MariaDB [test]> select rand();
+--------+
| rand() |
+--------+
|      0 |
+--------+
1 row in set (0.00 sec)

          I don't see this problem in Percona. 

          commit e64f5d8f758bcc1a8856ba9fba01780533f80747
Author: Oleksandr Byelkin <sanja@mariadb.com>
Date:   Sun Oct 26 16:27:54 2014 +0100

    Fixed test suite global variable saving

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                relates to

                Task - A task that needs to be done. MDEV-5231 Per query variables from Percona Server [patch]

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

                Technical task - A technical task. MDEV-6923 Testing for SET STATEMENT .. FOR (MDEV-5231, per-query variables)

                • Major - Major loss of function.
                • Closed

                  Activity

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                  sanja Oleksandr Byelkin added a comment -

                  The variable is prohibited in SET STATEMENT for now.

                  Show
                  sanja Oleksandr Byelkin added a comment - The variable is prohibited in SET STATEMENT for now.
                  Hide
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                  sanja Oleksandr Byelkin added a comment -

                  variables can be turned to usual ones

                  Show
                  sanja Oleksandr Byelkin added a comment - variables can be turned to usual ones
                  Hide
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                  sanja Oleksandr Byelkin added a comment -

                  They can not to be turned to usual variables because they do not have default value, but its value could be fetched.

                  Show
                  sanja Oleksandr Byelkin added a comment - They can not to be turned to usual variables because they do not have default value, but its value could be fetched.
                  Hide
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                  sanja Oleksandr Byelkin added a comment -

                  revision-id: 7ceff99ff25b74bb188848ce0e5f9e2f1ddac3d0
                  parent(s): 9f4ee16bf351ea2969d73abcdea92e70538c723c
                  committer: Oleksandr Byelkin
                  branch nick: server
                  timestamp: 2015-03-11 11:02:13 +0100
                  message:

                  MDEV-6954: SET STATEMENT rand_seedX = ...FOR ... makes the next rand() to return 0

                  The variables now return real values. They can't be made usual variables because they do not have DEFAULT value.

                  Show
                  sanja Oleksandr Byelkin added a comment - revision-id: 7ceff99ff25b74bb188848ce0e5f9e2f1ddac3d0 parent(s): 9f4ee16bf351ea2969d73abcdea92e70538c723c committer: Oleksandr Byelkin branch nick: server timestamp: 2015-03-11 11:02:13 +0100 message: MDEV-6954 : SET STATEMENT rand_seedX = ...FOR ... makes the next rand() to return 0 The variables now return real values. They can't be made usual variables because they do not have DEFAULT value.
                  Hide
                  Permalink
                  sanja Oleksandr Byelkin added a comment -

                  revision-id: 21eea36bfdc30447fb2f8607d53aba5df1082834
                  parent(s): 9f4ee16bf351ea2969d73abcdea92e70538c723c
                  committer: Oleksandr Byelkin
                  branch nick: server
                  timestamp: 2015-03-13 17:09:14 +0100
                  message:

                  MDEV-6954: SET STATEMENT rand_seedX = ...FOR ... makes the next rand() to return 0

                  The variables now return real values. They can't be made usual variables because they do not have DEFAULT value.

                  Show
                  sanja Oleksandr Byelkin added a comment - revision-id: 21eea36bfdc30447fb2f8607d53aba5df1082834 parent(s): 9f4ee16bf351ea2969d73abcdea92e70538c723c committer: Oleksandr Byelkin branch nick: server timestamp: 2015-03-13 17:09:14 +0100 message: MDEV-6954 : SET STATEMENT rand_seedX = ...FOR ... makes the next rand() to return 0 The variables now return real values. They can't be made usual variables because they do not have DEFAULT value.
                  Hide
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                  serg Sergei Golubchik added a comment -

                  ok to push

                  Show
                  serg Sergei Golubchik added a comment - ok to push

                    People

                    • Assignee:
                      sanja Oleksandr Byelkin
                      Reporter:
                      elenst Elena Stepanova
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                      Dates

                      • Created:
                        Updated:
                        Resolved: