Exchanging Partitions and Subpartitions with Tables Records: 0 Duplicates: 0 Warnings: 0 The number following  COALESCE PARTITION  is the number of partitions to merge into the remainder—in other words, it is the number of partitions to remove from the table. Attempting to remove more partitions than are in the table results in an error like this one: mysql>  ALTER TABLE clients COALESCE PARTITION 18; ERROR 1478 (HY000): Cannot remove all partitions, use DROP TABLE instead To increase the number of partitions for the  clients  table from 12 to 18, use  ALTER TABLE ... ADD PARTITION  as shown here: ALTER TABLE clients ADD PARTITION PARTITIONS 6; In MySQL 8.0, it is possible to exchange a table partition or subpartition with a table using  ALTER TABLE pt  EXCHANGE PARTITION  p  WITH TABLE  nt , where  pt  is the partitioned table and  p  is the partition or subpartition of  pt  to be exchanged with unpartitioned table  nt , provided that the following statements are true: 24.3.3 Exchanging Partitions and Subpartitions with Tables 1. Table  nt  is not itself partitioned. 2. Table  nt  is not a temporary table. 3. The structures of tables  pt  and  nt  are otherwise identical. 4. Table  nt  contains no foreign key references, and no other table has any foreign keys that refer to  nt . 5. There are no rows in  nt  that lie outside the boundaries of the partition definition for  p . This condition does not apply if  WITHOUT VALIDATION  is used. 6. For  InnoDB  tables, both tables use the same row format. To determine the row format of an  InnoDB table, query  INFORMATION_SCHEMA.INNODB_TABLES . 7. nt  does not have any partitions that use the  DATA DIRECTORY  option. This restriction is lifted for InnoDB  tables in MySQL 8.0.14 and later. In addition to the  ALTER ,  INSERT , and  CREATE  privileges usually required for  ALTER TABLE  statements, you must have the  DROP  privilege to perform  ALTER TABLE ... EXCHANGE PARTITION . You should also be aware of the following effects of  ALTER TABLE ... EXCHANGE PARTITION : The syntax for  ALTER TABLE ... EXCHANGE PARTITION  is shown here, where  pt  is the partitioned table,  p  is the partition (or subpartition) to be exchanged, and  nt  is the nonpartitioned table to be exchanged with  p : •Executing  ALTER TABLE ... EXCHANGE PARTITION  does not invoke any triggers on either the partitioned table or the table to be exchanged. •Any  AUTO_INCREMENT  columns in the exchanged table are reset. •The  IGNORE  keyword has no effect when used with  ALTER TABLE ... EXCHANGE PARTITION . ALTER TABLE  pt EXCHANGE PARTITION  p WITH TABLE  nt ; Optionally, you can append  WITH VALIDATION  or  WITHOUT VALIDATION . When  WITHOUT VALIDATION  is specified, the  ALTER TABLE ... EXCHANGE PARTITION  operation does not perform 4694