Adding, removing, and renaming a secondary index

Adding an index

ADD INDEX: Adds an index with the specified name and type for a given set of columns. The code below adds a global index named title_index for the title column.

ALTER TABLE `series` ADD INDEX `title_index` GLOBAL ON (`title`);

You can specify any index parameters from the CREATE TABLE command.

You can also add a secondary index using the YDB CLI table index command.

Altering an index

Indexes have type-specific parameters that can be tuned. Global indexes, whether synchronous or asynchronous, are implemented as hidden tables, and their automatic partitioning settings can be adjusted just like those of regular tables.

ALTER TABLE <table_name> ALTER INDEX <index_name> SET <partitioning_setting_name> <value>;
ALTER TABLE <table_name> ALTER INDEX <index_name> SET (<partitioning_setting_name_1> = <value_1>, ...);

• <table_name>: The name of the table whose index is to be modified.
• <index_name>: The name of the index to be modified.
• <partitioning_setting_name>: The name of the setting to be modified, which should be one of the following:
  • AUTO_PARTITIONING_BY_SIZE
  • AUTO_PARTITIONING_BY_LOAD
  • AUTO_PARTITIONING_PARTITION_SIZE_MB
  • AUTO_PARTITIONING_MIN_PARTITIONS_COUNT
  • AUTO_PARTITIONING_MAX_PARTITIONS_COUNT

• <value>: The new value for the setting. Possible values include:
  • ENABLED or DISABLED for the AUTO_PARTITIONING_BY_SIZE and AUTO_PARTITIONING_BY_LOAD settings
  • An integer of Uint64 type for the other settings

Example

The query in the following example enables automatic partitioning by load for the index named title_index of table series and sets its minimum partition count to 5:

ALTER TABLE `series` ALTER INDEX `title_index` SET (
    AUTO_PARTITIONING_BY_LOAD = ENABLED,
    AUTO_PARTITIONING_MIN_PARTITIONS_COUNT = 5
);

Deleting an index

DROP INDEX: Deletes the index with the specified name. The code below deletes the index named title_index.

ALTER TABLE `series` DROP INDEX `title_index`;

You can also remove a secondary index using the YDB CLI table index command.

Renaming an index

RENAME INDEX: Renames the index with the specified name.

If an index with the new name exists, an error is returned.

Replacement of atomic indexes under load is supported by the command ydb table index rename in the YDB CLI and by YDB SDK ad-hoc methods.

Example of index renaming:

ALTER TABLE `series` RENAME INDEX `title_index` TO `title_index_new`;