TimeScale Notes: Difference between revisions
Ian.readman (talk | contribs) Created page with "== TimeScale Compression == Check Distinct Values --------------------- -- n_distinct (-1 = Unique, 1 = All The Same) SELECT tablename, attname, most_common_vals, most_common_freqs, n_distinct FROM pg_stats -- WHERE tablename = '<TableName>'; WHERE schemaname = '<SchemaName>'; == Compress Table == ALTER TABLE crypto_ticks SET (timescaledb.compress, timescaledb.compress_segmentby='symbol', timescaledb.compress_orderby='time DESC'); SELECT compress_chunk(..." |
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== TimeScale Compression == | == TimeScale Compression == | ||
Check Distinct Values | == Check Distinct Values == | ||
-- n_distinct (-1 = Unique, 1 = All The Same) | -- n_distinct (-1 = Unique, 1 = All The Same) | ||
SELECT tablename, attname, most_common_vals, most_common_freqs, n_distinct | SELECT tablename, attname, most_common_vals, most_common_freqs, n_distinct |
Revision as of 20:21, 7 April 2025
TimeScale Compression
Check Distinct Values
-- n_distinct (-1 = Unique, 1 = All The Same) SELECT tablename, attname, most_common_vals, most_common_freqs, n_distinct FROM pg_stats -- WHERE tablename = '<TableName>'; WHERE schemaname = '<SchemaName>';
Compress Table
ALTER TABLE crypto_ticks SET (timescaledb.compress,
timescaledb.compress_segmentby='symbol', timescaledb.compress_orderby='time DESC');
SELECT compress_chunk(c) from show_chunks('crypto_ticks') c;
Check Compression
SELECT pg_size_pretty(before_compression_total_bytes) as before,
pg_size_pretty(after_compression_total_bytes) as after FROM hypertable_compression_stats('crypto_ticks');
Compression Policy
SELECT add_compression_policy('crypto_ticks', INTERVAL '8 days');
https://docs.timescale.com/tutorials/latest/financial-tick-data/financial-tick-compress/
HyperCore: Since version 2.18.0
https://docs.timescale.com/use-timescale/latest/compression/ (Old)
https://docs.timescale.com/use-timescale/latest/hypercore/ (New)