Month: March 2024
Make SHOW as good as SELECT even with InnoDB
Here’s a snippet of what I’d like SHOW ENGINE INNODB STATUS to look like:
as opposed to what the server sends:
... -------- FILE I/O -------- Pending flushes (fsync): 0 295 OS file reads, 1 OS file writes, 1 OS fsyncs 0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s ...
In my last post I described a way to
Make SHOW as good as SELECT”
which was possible because most result sets from SHOW etc. are at least table-like, but
STATUS’s wall of text isn’t table-like. So I forced it into a table with these basic rules:
- A line inside ——s, like FILE I/O, is the category of what follows.
- Otherwise a line is a row but if it contains commas it is multiple rows.
- Numbers can usually be extracted from text as different columns..
After that there’s still a bunch of fiddling, I put the details in source-code comments.
Version 2.3
The new features related to SHOW etc. are now in a released version as well as in source code,
downloadable from github.
In the rest of this post I’ll show a complete result from SHOW ENGINE INNODB STATUS; (“before”),
and the same data from SHOW ENGINE INNODB STATUS WHERE 1 > 0; after ocelot_statement_syntax_checker
has been set to ‘7’ (“after”). (Instead of copying the Grid Widget I copied from the History Widget
after setting Max Row Count to 100.)
“before”
| InnoDB | | ===================================== 2024-03-19 12:39:45 0x7f80f01f3700 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 43 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 0 srv_active, 2455 srv_idle srv_master_thread log flush and writes: 2454 ---------- SEMAPHORES ---------- ------------ TRANSACTIONS ------------ Trx id counter 754 Purge done for trx's n:o < 0 undo n:o < 0 state: running but idle History list length 0 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION (0x7f8111334680), not started 0 lock struct(s), heap size 1128, 0 row lock(s) ---TRANSACTION (0x7f8111333b80), not started 0 lock struct(s), heap size 1128, 0 row lock(s) -------- FILE I/O -------- Pending flushes (fsync): 0 295 OS file reads, 1 OS file writes, 1 OS fsyncs 0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s --- LOG --- Log sequence number 463193 Log flushed up to 463193 Pages flushed up to 362808 Last checkpoint at 362808 ---------------------- BUFFER POOL AND MEMORY ---------------------- Total large memory allocated 167772160 Dictionary memory allocated 853016 Buffer pool size 8064 Free buffers 7647 Database pages 417 Old database pages 0 Modified db pages 164 Percent of dirty pages(LRU & free pages): 2.033 Max dirty pages percent: 90.000 Pending reads 0 Pending writes: LRU 0, flush list 0 Pages made young 0, not young 0 0.00 youngs/s, 0.00 non-youngs/s Pages read 273, created 144, written 0 0.00 reads/s, 0.00 creates/s, 0.00 writes/s No buffer pool page gets since the last printout Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s LRU len: 417, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] -------------- ROW OPERATIONS -------------- 0 read views open inside InnoDB state: sleeping ---------------------------- END OF INNODB MONITOR OUTPUT ============================ |
“after”
/