Online DDL Operations •To avoid accidentally making the table unavailable for reads, writes, or both, during an in-place  ALTER TABLE  operation, specify a clause on the  ALTER TABLE  statement such as  LOCK=NONE  (permit reads and writes) or  LOCK=SHARED  (permit reads). The operation halts immediately if the requested level of concurrency is not available. •To compare performance between algorithms, run a statement with  ALGORITHM=INSTANT , ALGORITHM=INPLACE  and  ALGORITHM=COPY . You can also run a statement with the old_alter_table  configuration option enabled to force the use of  ALGORITHM=COPY . •To avoid tying up the server with an  ALTER TABLE  operation that copies the table, include ALGORITHM=INSTANT  or  ALGORITHM=INPLACE . The statement halts immediately if it cannot use the specified algorithm. •Index Operations •Primary Key Operations •Column Operations •Generated Column Operations •Foreign Key Operations •Table Operations •Tablespace Operations •Partitioning Operations 15.12.1 Online DDL Operations Online support details, syntax examples, and usage notes for DDL operations are provided under the following topics in this section. The following table provides an overview of online DDL support for index operations. An asterisk indicates additional information, an exception, or a dependency. For details, see Syntax and Usage Notes. Index Operations Table 15.16 Online DDL Support for Index Operations Operation Instant In Place Rebuilds Table Permits Concurrent DML Only Modifies Metadata Creating or adding a secondary index No Yes No Yes No Dropping an index No Yes No Yes Yes Renaming an index No Yes No Yes Yes Adding a FULLTEXT index No Yes* No* No No 3176