rec.Error() } return keyspaces, nil } In the first chunk of highlighted code, rec records an error of a single keyspace. In the second chunk of highlighted code, GetKeySpaces return nil and the error

chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so --default-retries=512 TABLE demo MODIFY id BIGINT • ALTER WITH 'gh-ost' '--allow-nullable-unique-key --chunk-size 200' TABLE demo MODIFY id BIGINT Do not override the following flags: alter, database, table

not overload the primary. • We issue a DELETE FROM my_table LIMIT 50 ; 10-100 are normally good chunk sizes. Order of purging does not matter. 47 It’s important to note that the DELETE statement actually chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so

not overload the primary. • We issue a DELETE FROM my_table LIMIT 50 ; 10-100 are normally good chunk sizes. Order of purging does not matter. It’s important to note that the DELETE statement actually chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so --default-retries=512'; • vtctl ApplySchema -ddl_strategy "gh-ost --allow-nullable-unique-key --chunk-size 200" ... Note: Do not override the following flags: alter, database, table, execute, max-lag

not overload the primary. • We issue a DELETE FROM my_table LIMIT 50 ; 10-100 are normally good chunk sizes. Order of purging does not matter. It’s important to note that the DELETE statement actually chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so --default-retries=512'; • vtctl ApplySchema -ddl_strategy "gh-ost --allow-nullable-unique-key --chunk-size 200" ... Note: Do not override the following flags: alter, database, table, execute, max-lag

not overload the primary. • We issue a DELETE FROM my_table LIMIT 50 ; 10-100 are normally good chunk sizes. Order of purging does not matter. It’s important to note that the DELETE statement actually chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so --default-retries=512'; • vtctl ApplySchema -ddl_strategy "gh-ost --allow-nullable-unique-key --chunk-size 200" ... Note: Do not override the following flags: alter, database, table, execute, max-lag

chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so

chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so

chunks. After each chunk is copied, replication is resumed until it’s caught up. VReplication ensures that only changes that affect existing rows are applied. Following this another chunk is copied, and so