Bug #81632 | MySQL 5.7 GLOBAL_STATUS table lost much of the data | ||
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Submitted: | 28 May 2016 15:05 | Modified: | 8 Jun 2016 7:33 |
Reporter: | Peter Zaitsev | Email Updates: | |
Status: | Not a Bug | Impact on me: | |
Category: | MySQL Server: Performance Schema | Severity: | S3 (Non-critical) |
Version: | 5.7.11, 5.7.12 | OS: | Any |
Assigned to: | Marc ALFF | CPU Architecture: | Any |
[28 May 2016 15:05]
Peter Zaitsev
[28 May 2016 15:26]
Peter Laursen
On 5.7.12 (Windows 64 bit server) I get SELECT * FROM PERFORMANCE_SCHEMA.GLOBAL_STATUS; (will attach a text file as it is too long for this system) .. what seems ok to me.
[28 May 2016 15:27]
Peter Laursen
SELECT * FROM PERFORMANCE_SCHEMA.GLOBAL_STATUS result
Attachment: status.txt (text/plain), 20.07 KiB.
[28 May 2016 15:28]
Peter Zaitsev
Peter, Do you get Same number of rows when you do SHOW GLOBAL STATUS vs SELECT * FROM PERFORMANCE_SCHEMA.GLOBAL_STATUS ? Can you just paste row counts ?
[28 May 2016 15:30]
Peter Zaitsev
Peter, Checked your status - see you do not have nearly all Com_XXX out there There is not even Com_Select !
[28 May 2016 15:36]
Peter Zaitsev
OK, This looks to be the documented behavior http://dev.mysql.com/doc/refman/5.7/en/performance-schema-status-variable-tables.html "The Performance Schema does not collect statistics for Com_xxx status variables in the status variable tables. To obtain global and per-session statement execution counts, use the events_statements_summary_global_by_event_name and events_statements_summary_by_thread_by_event_name tables, respectively. For example:" I do not think it is a great decision though. Now I can get a lot of values from "SHOW GLOBAL STATUS" so they are there but I lost convenient SQL interface to them as INFORMATION_SCHEMA.GLOBAL_STATUS is gone and Performance Schema global status does not collect some of them.
[28 May 2016 16:08]
Peter Laursen
@PZ - you are absolutely right! My result rowcounts are: SELECT * FROM P_S.GLOBAL_STATUS: 206 SHOW GLOBAL STATUS: 353
[28 May 2016 16:10]
Peter Laursen
SHOW GLOBAL STATUS result
Attachment: showgloba.txt (text/plain), 34.32 KiB.
[28 May 2016 16:23]
Peter Laursen
This is also a surprise for me.
[30 May 2016 7:22]
MySQL Verification Team
Hello Peter, Thank you for the report and feedback! Thanks, Umesh
[8 Jun 2016 7:33]
Marc ALFF
This is not a bug, it works as intended. SHOW GLOBAL STATUS historically printed both: - general status counters - statement statistics (only the count) With the performance schema, statement statistics are in the statements related tables. If P_S GLOBAL STATUS should also contain statement statistics, consider this: should it be expanded to include transactions, stages, waits, memory, and any future instrumentation statistics as well (probably not) ? Why treating statements counters differently then ?