adding documentation

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Shlomi Noach 2016-05-23 11:35:04 +02:00
parent 5a5f43d15b
commit 0050665393

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@ -42,3 +42,18 @@ You now have the time to verify the tool works correctly. You may checksum the e
It's your job to: It's your job to:
- Drop the ghost table (at your leisure, you should be aware that a `DROP` can be a lengthy operation) - Drop the ghost table (at your leisure, you should be aware that a `DROP` can be a lengthy operation)
- Start replication back (via `START SLAVE`) - Start replication back (via `START SLAVE`)
### Examples
Simple:
```shell
$ gh-osc --host=myhost.com --conf=/etc/gh-ost.cnf --database=test --table=sample_table --alter="engine=innodb" --chunk-size=2000 --max-load=Threads_connected=20 --initially-drop-ghost-table --initially-drop-old-table --test-on-replica --verbose --execute
```
Elaborate:
```shell
$ gh-osc --host=myhost.com --conf=/etc/gh-ost.cnf --database=test --table=sample_table --alter="engine=innodb" --chunk-size=2000 --max-load=Threads_connected=20 --switch-to-rbr --initially-drop-ghost-table --initially-drop-old-table --test-on-replica --postpone-swap-tables-flag-file=/tmp/ghost-postpone.flag --exact-rowcount --allow-nullable-unique-key --verbose --execute
```
- Count exact number of rows (makes ETA estimation very good). This goes at the expense of paying the time for issuing a `SELECT COUNT(*)` on your table. We use this lovingly.
- Automatically switch to `RBR` if replica is configured as `SBR`. See also: [migrating with SBR](migrating-with-sbr.md)
- allow iterating on a `UNIQUE KEY` that has `NULL`able columns (at your own risk)