Grand Unified Configuration (GUC) parameters

You use the following Grand Unified Configuration (GUC) parameters to optimize the behavior of your Tiger Cloud service.

The namespace of each GUC is timescaledb. To set a GUC you specify <namespace>.<GUC name>. For example:


SET timescaledb.enable_tiered_reads = true;

Name	Type	Default	Description
`auto_sparse_indexes`	`BOOLEAN`	`true`	The hypertable columns that are used as index keys will have suitable sparse indexes when compressed. Must be set at the moment of chunk compression, e.g. when the `compress_chunk()` is called.
`bgw_log_level`	`ENUM`	`WARNING`	Log level for the scheduler and workers of the background worker subsystem. Requires configuration reload to change.
`compress_truncate_behaviour`	`ENUM`	`COMPRESS_TRUNCATE_ONLY`	Defines how truncate behaves at the end of compression. 'truncate_only' forces truncation. 'truncate_disabled' deletes rows instead of truncate. 'truncate_or_delete' allows falling back to deletion.
`compression_batch_size_limit`	`INTEGER`	`1000`	Setting this option to a number between 1 and 999 will force compression to limit the size of compressed batches to that amount of uncompressed tuples.Setting this to 0 defaults to the max batch size of 1000. min: `1`, max: `1000`
`compression_orderby_default_function`	`STRING`	`"_timescaledb_functions.get_orderby_defaults"`	Function to use for calculating default order_by setting for compression
`compression_segmentby_default_function`	`STRING`	`"_timescaledb_functions.get_segmentby_defaults"`	Function to use for calculating default segment_by setting for compression
`current_timestamp_mock`	`STRING`	`NULL`	this is for debugging purposes
`debug_allow_cagg_with_deprecated_funcs`	`BOOLEAN`	`false`	this is for debugging/testing purposes
`debug_bgw_scheduler_exit_status`	`INTEGER`	`0`	this is for debugging purposes min: `0`, max: `255`
`debug_compression_path_info`	`BOOLEAN`	`false`	this is for debugging/information purposes
`debug_have_int128`	`BOOLEAN`	`#ifdef HAVE_INT128 true`	this is for debugging purposes
`debug_require_batch_sorted_merge`	`BOOLEAN`	`false`	this is for debugging purposes
`debug_require_vector_agg`	`ENUM`	`DRO_Allow`	this is for debugging purposes
`debug_require_vector_qual`	`ENUM`	`DRO_Allow`	this is for debugging purposes, to let us check if the vectorized quals are used or not. EXPLAIN differs after PG15 for custom nodes, and using the test templates is a pain
`debug_toast_tuple_target`	`INTEGER`	`/* bootValue = */ 128`	this is for debugging purposes min: `/* minValue = / 1`, max: `/ maxValue = */ 65535`
`default_hypercore_use_access_method`	`BOOLEAN`	`false`	gettext_noop(Sets the global default for using Hypercore TAM when compressing chunks.)
`enable_bool_compression`	`BOOLEAN`	`true`	Enable bool compression
`enable_bulk_decompression`	`BOOLEAN`	`true`	Increases throughput of decompression, but might increase query memory usage
`enable_cagg_reorder_groupby`	`BOOLEAN`	`true`	Enable group by clause reordering for continuous aggregates
`enable_cagg_sort_pushdown`	`BOOLEAN`	`true`	Enable pushdown of ORDER BY clause for continuous aggregates
`enable_cagg_watermark_constify`	`BOOLEAN`	`true`	Enable constifying cagg watermark for real-time caggs
`enable_cagg_window_functions`	`BOOLEAN`	`false`	Allow window functions in continuous aggregate views
`enable_chunk_append`	`BOOLEAN`	`true`	Enable using chunk append node
`enable_chunk_skipping`	`BOOLEAN`	`false`	Enable using chunk column stats to filter chunks based on column filters
`enable_chunkwise_aggregation`	`BOOLEAN`	`true`	Enable the pushdown of aggregations to the chunk level
`enable_columnarscan`	`BOOLEAN`	`true`	A columnar scan replaces sequence scans for columnar-oriented storage and enables storage-specific optimizations like vectorized filters. Disabling columnar scan will make PostgreSQL fall back to regular sequence scans.
`enable_compressed_direct_batch_delete`	`BOOLEAN`	`true`	Enable direct batch deletion in compressed chunks
`enable_compressed_skipscan`	`BOOLEAN`	`true`	Enable SkipScan for distinct inputs over compressed chunks
`enable_compression_indexscan`	`BOOLEAN`	`false`	Enable indexscan during compression, if matching index is found
`enable_compression_ratio_warnings`	`BOOLEAN`	`true`	Enable warnings for poor compression ratio
`enable_compression_wal_markers`	`BOOLEAN`	`true`	Enable the generation of markers in the WAL stream which mark the start and end of compression operations
`enable_compressor_batch_limit`	`BOOLEAN`	`false`	Enable compressor batch limit for compressors which can go over the allocation limit (1 GB). This feature willlimit those compressors by reducing the size of the batch and thus avoid hitting the limit.
`enable_constraint_aware_append`	`BOOLEAN`	`true`	Enable constraint exclusion at execution time
`enable_constraint_exclusion`	`BOOLEAN`	`true`	Enable planner constraint exclusion
`enable_custom_hashagg`	`BOOLEAN`	`false`	Enable creating custom hash aggregation plans
`enable_decompression_sorted_merge`	`BOOLEAN`	`true`	Enable the merge of compressed batches to preserve the compression order by
`enable_delete_after_compression`	`BOOLEAN`	`false`	Delete all rows after compression instead of truncate
`enable_deprecation_warnings`	`BOOLEAN`	`true`	Enable warnings when using deprecated functionality
`enable_direct_compress_copy`	`BOOLEAN`	`false`	Enable experimental support for direct compression during COPY
`enable_direct_compress_copy_client_sorted`	`BOOLEAN`	`false`	Correct handling of data sorting by the user is required for this option.
`enable_direct_compress_copy_sort_batches`	`BOOLEAN`	`true`	Enable batch sorting during direct compress COPY
`enable_dml_decompression`	`BOOLEAN`	`true`	Enable DML decompression when modifying compressed hypertable
`enable_dml_decompression_tuple_filtering`	`BOOLEAN`	`true`	Recheck tuples during DML decompression to only decompress batches with matching tuples
`enable_event_triggers`	`BOOLEAN`	`false`	Enable event triggers for chunks creation
`enable_exclusive_locking_recompression`	`BOOLEAN`	`false`	Enable getting exclusive lock on chunk during segmentwise recompression
`enable_foreign_key_propagation`	`BOOLEAN`	`true`	Adjust foreign key lookup queries to target whole hypertable
`enable_hypercore_scankey_pushdown`	`BOOLEAN`	`true`	Enabling this setting might lead to faster scans when query qualifiers match Hypercore segmentby and orderby columns.
`enable_job_execution_logging`	`BOOLEAN`	`false`	Retain job run status in logging table
`enable_merge_on_cagg_refresh`	`BOOLEAN`	`false`	Enable MERGE statement on cagg refresh
`enable_now_constify`	`BOOLEAN`	`true`	Enable constifying now() in query constraints
`enable_null_compression`	`BOOLEAN`	`true`	Enable null compression
`enable_optimizations`	`BOOLEAN`	`true`	Enable TimescaleDB query optimizations
`enable_ordered_append`	`BOOLEAN`	`true`	Enable ordered append optimization for queries that are ordered by the time dimension
`enable_parallel_chunk_append`	`BOOLEAN`	`true`	Enable using parallel aware chunk append node
`enable_qual_propagation`	`BOOLEAN`	`true`	Enable propagation of qualifiers in JOINs
`enable_rowlevel_compression_locking`	`BOOLEAN`	`false`	Use only if you know what you are doing
`enable_runtime_exclusion`	`BOOLEAN`	`true`	Enable runtime chunk exclusion in ChunkAppend node
`enable_segmentwise_recompression`	`BOOLEAN`	`true`	Enable segmentwise recompression
`enable_skipscan`	`BOOLEAN`	`true`	Enable SkipScan for DISTINCT queries
`enable_skipscan_for_distinct_aggregates`	`BOOLEAN`	`true`	Enable SkipScan for DISTINCT aggregates
`enable_sparse_index_bloom`	`BOOLEAN`	`true`	This sparse index speeds up the equality queries on compressed columns, and can be disabled when not desired.
`enable_tiered_reads`	`BOOLEAN`	`true`	Enable reading of tiered data by including a foreign table representing the data in the object storage into the query plan
`enable_transparent_decompression`	`ENUM`	`1`	Enable transparent decompression when querying hypertable
`enable_tss_callbacks`	`BOOLEAN`	`true`	Enable ts_stat_statements callbacks
`enable_vectorized_aggregation`	`BOOLEAN`	`true`	Enable vectorized aggregation for compressed data
`hypercore_arrow_cache_max_entries`	`INTEGER`	`25000`	The max number of decompressed arrow segments that can be cached before entries are evicted. This mainly affects the performance of index scans on the Hypercore TAM when segments are accessed in non-sequential order. min: `1`, max: `INT_MAX`
`hypercore_copy_to_behavior`	`ENUM`	`HYPERCORE_COPY_NO_COMPRESSED_DATA`	Set to 'all_data' to return both compressed and uncompressed data via the Hypercore table when using COPY TO. Set to 'no_compressed_data' to skip compressed data.
`hypercore_indexam_whitelist`	`STRING`	`"btree,hash"`	gettext_noop(List of index access method names supported by hypercore.)
`last_tuned`	`STRING`	`NULL`	records last time timescaledb-tune ran
`last_tuned_version`	`STRING`	`NULL`	version of timescaledb-tune used to tune
`license`	`STRING`	`TS_LICENSE_DEFAULT`	Determines which features are enabled
`materializations_per_refresh_window`	`INTEGER`	`10`	The maximal number of individual refreshes per cagg refresh. If more refreshes need to be performed, they are merged into a larger single refresh. min: `0`, max: `INT_MAX`
`max_cached_chunks_per_hypertable`	`INTEGER`	`1024`	Maximum number of chunks stored in the cache min: `0`, max: `65536`
`max_open_chunks_per_insert`	`INTEGER`	`1024`	Maximum number of open chunk tables per insert min: `0`, max: `PG_INT16_MAX`
`max_tuples_decompressed_per_dml_transaction`	`INTEGER`	`100000`	If the number of tuples exceeds this value, an error will be thrown and transaction rolled back. Setting this to 0 sets this value to unlimited number of tuples decompressed. min: `0`, max: `2147483647`
`restoring`	`BOOLEAN`	`false`	In restoring mode all timescaledb internal hooks are disabled. This mode is required for restoring logical dumps of databases with timescaledb.
`shutdown_bgw_scheduler`	`BOOLEAN`	`false`	this is for debugging purposes
`skip_scan_run_cost_multiplier`	`REAL`	`1.0`	Default is 1.0 i.e. regularly estimated SkipScan run cost, 0.0 will make SkipScan to have run cost = 0 min: `0.0`, max: `1.0`
`telemetry_level`	`ENUM`	`TELEMETRY_DEFAULT`	Level used to determine which telemetry to send

Version: 2.21.0

Grand Unified Configuration (GUC) parameters

Related Content