. . . . . . . . . . . . . . . . . . . . . . . . . 416 Applying, auditing, and controlling Online DDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 Running migrations . . . . . . . . 429 Online DDL strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Specifying a DDL strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 Choosing a DDL strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . 393 Applying, auditing, and controlling Online DDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 Running migrations . . . . . . . . 405 Online DDL strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Specifying a DDL strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Choosing a DDL strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Online DDL Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469 Applying, auditing, and controlling Online DDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469 Running migrations . . . . . . . . 482 Online DDL strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 Specifying a DDL strategy . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 ddl_strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . implement. Asking for a safe DROP Safe DROP TABLEs participate in the Online DDL flow. When a user chooses an online ddl_strategy, the user’s DROP TABLE statement implicitly translates to a RENAME TABLE later deprecate GTID as an explicit event. Instead, we can send the GTID as part of the COMMIT or DDL message, which is where it’s actually used. This will allow us to tighten some code in vplayer. Without

requires a fixed schema. This will be made more flexible in the future. There will also be a custom DDL syntax. For now, a message table must be created like this: create table my_message( time_scheduled -sql_file=user_table.sql user Permitted schema changes The ApplySchema command supports a limited set of DDL statements. In addition, Vitess rejects some schema changes because large changes can slow replication replication and may reduce the availability of your overall system. The following list identifies types of DDL statements that Vitess supports: • CREATE TABLE • CREATE INDEX • CREATE VIEW • ALTER TABLE • ALTER

requires a fixed schema. This will be made more flexible in the future. There will also be a custom DDL syntax. For now, a message table must be created like this: create table my_message( time_scheduled and MySQL. For a list of unsup- ported queries, check out the test-suite cases. 51 DDL Vitess supports MySQL DDL, and will send ALTER TABLE statements to each of the underlying tablet servers. For large -sql_file=user_table.sql user Permitted schema changes The ApplySchema command supports a limited set of DDL statements. In addition, Vitess rejects some schema changes because large changes can slow replication

requires a fixed schema. This will be made more flexible in the future. There will also be a custom DDL syntax. For now, a message table must be created like this: create table my_message( time_scheduled -sql_file=user_table.sql user Permitted schema changes The ApplySchema command supports a limited set of DDL statements. In addition, Vitess rejects some schema changes because large changes can slow replication replication and may reduce the availability of your overall system. The following list identifies types of DDL statements that Vitess supports: • CREATE TABLE • CREATE INDEX • CREATE VIEW • ALTER TABLE • ALTER

requires a fixed schema. This will be made more flexible in the future. There will also be a custom DDL syntax. For now, a message table must be created like this: create table my_message( time_scheduled Vitess and MySQL. For a list of unsup- ported queries, check out the test-suite cases. DDL Vitess supports MySQL DDL, and will send ALTER TABLE statements to each of the underlying tablet servers. For large -sql_file=user_table.sql user Permitted schema changes The ApplySchema command supports a limited set of DDL statements. In addition, Vitess rejects some schema changes because large changes can slow replication

NoPlan select * from user union select * from user union NoPlan set a=1 set NoPlan create table a() DDL NoPlan explain select * from user explain NoPlan select * from music, user where id = 1 JOIN NoPlan Vitess RowCache • RowCache VS MySQL Buffer Pool • LRUCache • Base on binlog • DDL ? • key=prefix +body • every DDL —> prefix:=prefix+1 • lastest prefix + Body • vttable restart ? Vitess Cons