pt-duplicate-key-checker documentation does not explain how Size Duplicate Indexes is calculated
Bug #1415646 reported by
Greg
This bug affects 1 person
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Percona Toolkit moved to https://jira.percona.com/projects/PT |
Fix Released
|
Low
|
Frank Cizmich | ||
Bug Description
Using toolkit version 2.2.13 but also present in 2.2.12 and likely all back versions.
pt-duplicate-
What is it adding?
Does it add in all replicas? (likely not I would think)
If not, how does it choose which redundant index to include in the total?
Related branches
lp:~percona-toolkit-dev/percona-toolkit/pt-duplicate-key-checker-docs-dont-explain-how-Size-Duplicate-Indexes-is-calculated-1415646
- Percona Toolkit developers: Pending requested
-
Diff: 14 lines (+4/-0)1 file modifiedbin/pt-duplicate-key-checker (+4/-0)
| Changed in percona-toolkit: | |
| status: | New → In Progress |
| importance: | Undecided → Low |
| assignee: | nobody → Frank Cizmich (frank-cizmich) |
| milestone: | none → 2.2.14 |
Revision history for this message
| Frank Cizmich (frank-cizmich) wrote | #1 |
| Changed in percona-toolkit: | |
| status: | In Progress → Fix Committed |
| Changed in percona-toolkit: | |
| status: | Fix Committed → Fix Released |
Revision history for this message
| Shahriyar Rzayev (rzayev-sehriyar) wrote | #2 |
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Hello Greg,
"Size Duplicate Indexes" is simply the size in bytes that all the duplicate keys are occupying.
It is calculated using carefully crafted EXPLAIN queries.
To obtain the size of a duplicate key, the key length (in bytes) is multiplied by the number of rows in the table.
All of them are then added up for the final total.
This does not include the ones in the replicas.
Note that the number of rows reported by EXPLAIN is often just an estimate, so the figures are not exact.
It is fair that this should be explained in the docs.
Regards