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https://github.com/timescale/timescaledb.git
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a4a023e89a
For better understanding we've decided to rename the public API from
`{enable|disable}_column_stats` to `{enable|disable}_chunk_skipping`.
87 lines
3.9 KiB
SQL
87 lines
3.9 KiB
SQL
-- Enable tracking of statistics on a column of a hypertable.
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--
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-- hypertable - OID of the table to which the column belongs to
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-- column_name - The column to track statistics for
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-- if_not_exists - If set, and the entry already exists, generate a notice instead of an error
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CREATE FUNCTION @extschema@.enable_chunk_skipping(
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hypertable REGCLASS,
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column_name NAME,
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if_not_exists BOOLEAN = FALSE
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) RETURNS TABLE(column_stats_id INT, enabled BOOL)
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AS 'SELECT NULL,NULL' LANGUAGE SQL VOLATILE SET search_path = pg_catalog, pg_temp;
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-- Disable tracking of statistics on a column of a hypertable.
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--
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-- hypertable - OID of the table to remove from
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-- column_name - NAME of the column on which the stats are tracked
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-- if_not_exists - If set, and the entry does not exist,
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-- generate a notice instead of an error
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CREATE FUNCTION @extschema@.disable_chunk_skipping(
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hypertable REGCLASS,
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column_name NAME,
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if_not_exists BOOLEAN = FALSE
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) RETURNS TABLE(hypertable_id INT, column_name NAME, disabled BOOL)
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AS 'SELECT NULL,NULL,NULL' LANGUAGE SQL VOLATILE SET search_path = pg_catalog, pg_temp;
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-- Track statistics for columns of chunks from a hypertable.
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-- Currently, we track the min/max range for a given column across chunks.
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-- More statistics (like bloom filters) will be added in the future.
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--
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-- A "special" entry for a column with invalid chunk_id, PG_INT64_MAX,
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-- PG_INT64_MIN indicates that min/max ranges could be computed for this column
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-- for chunks.
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--
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-- The ranges can overlap across chunks. The values could be out-of-date if
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-- modifications/changes occur in the corresponding chunk and such entries
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-- should be marked as "invalid" to ensure that the chunk is in
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-- appropriate state to be able to use these values. Thus these entries
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-- are different from dimension_slice which is used for tracking partitioning
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-- column ranges which have different characteristics.
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--
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-- Currently this catalog supports datatypes like INT, SERIAL, BIGSERIAL,
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-- DATE, TIMESTAMP etc. by storing the ranges in bigint columns. In the
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-- future, we could support additional datatypes (which support btree style
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-- >, <, = comparators) by storing their textual representation.
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--
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CREATE TABLE _timescaledb_catalog.chunk_column_stats (
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id serial NOT NULL,
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hypertable_id integer NOT NULL,
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chunk_id integer NOT NULL,
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column_name name NOT NULL,
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range_start bigint NOT NULL,
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range_end bigint NOT NULL,
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valid boolean NOT NULL,
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-- table constraints
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CONSTRAINT chunk_column_stats_pkey PRIMARY KEY (id),
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CONSTRAINT chunk_column_stats_ht_id_chunk_id_colname_key UNIQUE (hypertable_id, chunk_id, column_name),
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CONSTRAINT chunk_column_stats_range_check CHECK (range_start <= range_end),
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CONSTRAINT chunk_column_stats_hypertable_id_fkey FOREIGN KEY (hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id),
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CONSTRAINT chunk_column_stats_chunk_id_fkey FOREIGN KEY (chunk_id) REFERENCES _timescaledb_catalog.chunk (id)
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);
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SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.chunk_column_stats', '');
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SELECT pg_catalog.pg_extension_config_dump(pg_get_serial_sequence('_timescaledb_catalog.chunk_column_stats', 'id'), '');
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GRANT SELECT ON _timescaledb_catalog.chunk_column_stats TO PUBLIC;
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GRANT SELECT ON _timescaledb_catalog.chunk_column_stats_id_seq TO PUBLIC;
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-- Remove foreign key constraints from compressed chunks
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DO $$
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DECLARE
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conrelid regclass;
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conname name;
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BEGIN
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FOR conrelid, conname IN
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SELECT
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con.conrelid::regclass,
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con.conname
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FROM _timescaledb_catalog.chunk ch
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JOIN pg_constraint con ON con.conrelid = format('%I.%I',schema_name,table_name)::regclass AND con.contype='f'
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WHERE NOT ch.dropped AND EXISTS(SELECT FROM _timescaledb_catalog.chunk ch2 WHERE NOT ch2.dropped AND ch2.compressed_chunk_id=ch.id)
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LOOP
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EXECUTE format('ALTER TABLE %s DROP CONSTRAINT %I', conrelid, conname);
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END LOOP;
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END $$;
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