Shulou(Shulou.com)06/01 Report--

Description of whether Online DDL locks the table, whether the rebuild table, inplace or copy algorithm:

Original: https://dev.mysql.com/doc/refman/5.6/en/innodb-create-index-overview.html?spm=5176.100239.blogcont64664.13.SpL8lH

OperationIn-Place?Rebuilds Table?Permits Concurrent DML?Only Modifies Metadata?NotesCREATE INDEX, ADD INDEXYes*No*YesNoRestrictions apply for FULLTEXT indexes; see next row.ADD FULLTEXT INDEXYes*No*NoNoAdding the first FULLTEXT index rebuilds the table if there is no user-defined FTS_DOC_ID column. Subsequent FULLTEXT indexes may be added on the same table without rebuilding the table.DROP INDEXYesNoYesYesOnly modifies table metadata.OPTIMIZE TABLEYes*YesYesNoPerformed in-place as of MySQL 5.6.17. In-place operation is not supported for tables withFULLTEXT indexes.Set column default valueYesNoYesYesOnly modifies table metadata.Change auto-incrementvalueYesNoYesNo*Modifies a value stored in memory, not the data file.Add foreign key constraintYes*NoYesYesThe INPLACE algorithm is supported when foreign_key_checks is disabled. Otherwise, only theCOPY algorithm is supported.Drop foreign key constraintYesNoYesYesforeign_key_checks can be enabled or disabled.Rename columnYesNoYes*YesTo permit concurrent DML, keep the same data type and only change the column name.Add columnYesYesYes*NoConcurrent DML is not permitted when adding an auto-increment column. Data is reorganized substantially, making it an expensive operation.Drop columnYesYesYesNoData is reorganized substantially, making it an expensive operation.Reorder columnsYesYesYesNoData is reorganized substantially, making it an expensive operation.Change ROW_FORMATpropertyYesYesYesNoData is reorganized substantially, making it an expensive operation.Change KEY_BLOCK_SIZEpropertyYesYesYesNoData is reorganized substantially, making it an expensive operation.Make column NULLYesYes*YesNoRebuilds the table in place. Data is reorganized substantially, making it an expensive operation.Make column NOT NULLYes*Yes*YesNoRebuilds the table in place. STRICT_ALL_TABLES or STRICT_TRANS_TABLES SQL_MODE is required for the operation to succeed. The operation fails if the column contains NULL values. As of 5.6.7, the server prohibits changes to foreign key columns that have the potential to cause loss of referential integrity. See Section 13.1.7, "ALTER TABLE Syntax". Data is reorganized substantially, making it an expensive operation.Change column data typeNoYesNoNoOnly supports ALGORITHM=COPYAdd primary keyYes*Yes*YesNoRebuilds the table in place. Data is reorganized substantially, making it an expensive operation.ALGORITHM=INPLACE is not permitted under certain conditions if columns have to be converted toNOT NULL.Drop primary key and add anotherYesYesYesNoData is reorganized substantially, making it an expensive operation.Drop primary keyNoYesNoNoOnly ALGORITHM=COPY supports dropping a primary key without adding a new one in the sameALTER TABLE statement.Convert character setNoYes*NoNoRebuilds the table if the new character encoding is different.Specify character setNoYes*NoNoRebuilds the table if the new character encoding is different.Rebuild with FORCEoptionYes*YesYesNoUses ALGORITHM=INPLACE as of MySQL 5.6.17. ALGORITHM=INPLACE is not supported for tables withFULLTEXT indexes. "null" rebuild usingALTER TABLE. ENGINE=INNODBYes*YesYesNoUses ALGORITHM=INPLACE as of MySQL 5.6.17. ALGORITHM=INPLACE is not supported for tables withFULLTEXT indexes.Set STATS_PERSISTENT,STATS_AUTO_RECALC,STATS_SAMPLE_PAGESpersistent statisticsoptionsYesNoYesYesOnly modifie

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