Add note about not supporting multiple ALTER TABLE operations (#1892)

Co-authored-by: Kolbe Kegel <kolbe@kolbekegel.com>
pingcap · Feb 28, 2020 · 4e4f057 · 4e4f057
1 parent bb5a71f
commit 4e4f057
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/reference/mysql-compatibility.md b/reference/mysql-compatibility.md
@@ -104,6 +104,7 @@ In TiDB DDL does not block reads or writes to tables while in operation. However
     - Only supports changing the `CHARACTER SET` attribute from `utf8` to `utf8mb4`.
 + `LOCK [=] {DEFAULT|NONE|SHARED|EXCLUSIVE}`: the syntax is supported, but is not applicable to TiDB. All DDL changes that are supported do not lock the table.
 + `ALGORITHM [=] {DEFAULT|INSTANT|INPLACE|COPY}`: the syntax for `ALGORITHM=INSTANT` and `ALGORITHM=INPLACE` is fully supported, but it works differently from MySQL because some operations that are `INPLACE` in MySQL are `INSTANT` in TiDB. The syntax `ALGORITHM=COPY` is not applicable to TIDB and returns a warning.
++ Multiple operations cannot be completed in a single `ALTER TABLE` statement. For example, it's not possible to add multiple columns or indexes in a single statement.
 
 + The following Table Options are not supported in syntax:
     - `WITH/WITHOUT VALIDATION`