Contents

citus v9.1.1 (December 18, 2019)

  • Fixes a bug causing SQL-executing UDFs to crash when passing in DDL

  • Fixes a bug that caused column_to_column_name to crash for invalid input

  • Fixes a bug that caused inserts into local tables w/ dist. subqueries to crash

  • Fixes a bug that caused some noop DML statements to fail

  • Fixes a bug that prevents dropping reference table columns

  • Fixes a crash in IN (.., NULL) queries

  • Fixes a crash when calling a distributed function from PL/pgSQL

  • Fixes an issue that caused CTEs to sometimes leak connections

  • Fixes strange errors in DML with unreachable sublinks

  • Prevents statements in SQL functions to run outside of a transaction

citus v9.1.0 (November 21, 2019)

  • Adds extensions to distributed object propagation infrastructure

  • Adds support for ALTER ROLE propagation

  • Adds support for aggregates in create_distributed_function

  • Adds support for expressions in reference joins

  • Adds support for returning RECORD in multi-shard queries

  • Adds support for simple IN subqueries on unique cols in repartition joins

  • Adds support for subqueries in HAVING clauses

  • Automatically distributes unary aggs w/ combinefunc and non-internal stype

  • Disallows distributed func creation when replication_model is 'statement'

  • Drops support for deprecated real-time and router executors

  • Fixes a bug in local execution that could cause missing rows in RETURNING

  • Fixes a bug that caused maintenance daemon to fail on standby nodes

  • Fixes a bug that caused other CREATE EXTENSION commands to take longer

  • Fixes a bug that prevented REFRESH MATERIALIZED VIEW

  • Fixes a bug when view is used in modify statements

  • Fixes a memory leak in adaptive executor when query returns many columns

  • Fixes underflow init of default values in worker extended op node creation

  • Fixes potential segfault in standard_planner inlining functions

  • Fixes an issue that caused failures in RHEL 6 builds

  • Fixes queries with repartition joins and group by unique column

  • Improves CTE/Subquery performance by pruning intermediate rslt broadcasting

  • Removes citus.worker_list_file GUC

  • Revokes usage from the citus schema from public

citus v9.0.1 (October 25, 2019)

  • Fixes a memory leak in the executor

  • Revokes usage from the citus schema from public

citus v9.0.0 (October 7, 2019)

  • Adds support for PostgreSQL 12

  • Adds UDFs to help with PostgreSQL upgrades

  • Distributes types to worker nodes

  • Introduces create_distributed_function UDF

  • Introduces local query execution for Citus MX

  • Implements infrastructure for routing CALL to MX workers

  • Implements infrastructure for routing SELECT function() to MX workers

  • Adds support for foreign key constraints between reference tables

  • Adds a feature flag to turn off CREATE TYPE propagation

  • Adds option citus.single_shard_commit_protocol

  • Adds support for EXPLAIN SUMMARY

  • Adds support for GENERATE ALWAYS AS STORED

  • Adds support for serial and smallserial in MX mode

  • Adds support for anon composite types on the target list in router queries

  • Avoids race condition between create_reference_table & master_add_node

  • Fixes a bug in schemas of distributed sequence definitions

  • Fixes a bug that caused run_command_on_colocated_placements to fail

  • Fixes a bug that leads to various issues when a connection is lost

  • Fixes a schema leak on CREATE INDEX statement

  • Fixes assert failure in bare SELECT FROM reference table FOR UPDATE in MX

  • Makes master_update_node MX compatible

  • Prevents pg_dist_colocation from multiple records for reference tables

  • Prevents segfault in worker_partition_protocol edgecase

  • Propagates ALTER FUNCTION statements for distributed functions

  • Propagates CREATE OR REPLACE FUNCTION for distributed functions

  • Propagates REINDEX on tables & indexes

  • Provides a GUC to turn of the new dependency propagation functionality

  • Uses 2PC in adaptive executor when dealing with replication factors above 1

citus v8.3.2 (August 09, 2019)

  • Fixes performance issues by skipping unnecessary relation access recordings

citus v8.3.1 (July 29, 2019)

  • Improves Adaptive Executor performance

citus v8.3.0 (July 10, 2019)

  • Adds a new distributed executor: Adaptive Executor

  • citus.enable_statistics_collection defaults to off (opt-in)

  • Adds support for CTEs in router planner for modification queries

  • Adds support for propagating SET LOCAL at xact start

  • Adds option to force master_update_node during failover

  • Deprecates master_modify_multiple_shards

  • Improves round robin logic on router queries

  • Creates all distributed schemas as superuser on a separate connection

  • Makes COPY adapt to connection use behaviour of previous commands

  • Replaces SESSION_LIFESPAN with configurable number of connections at xact end

  • Propagates ALTER FOREIGN TABLE commands to workers

  • Don't schedule tasks on inactive nodes

  • Makes DROP/VALIDATE CONSTRAINT tolerant of ambiguous shard extension

  • Fixes an issue with subquery map merge jobs as non-root

  • Fixes null pointers caused by partial initialization of ConnParamsHashEntry

  • Fixes errors caused by joins with shadowed aliases

  • Fixes a regression in outer joining subqueries introduced in 8.2.0

  • Fixes a crash that can occur under high memory load

  • Fixes a bug that selects wrong worker when using round-robin assignment

  • Fixes savepoint rollback after multi-shard modify/copy failure

  • Fixes bad foreign constraint name search

  • Fixes a bug that prevents stack size to be adjusted

citus v8.2.2 (June 11, 2019)

  • Fixes a bug in outer joins wrapped in subqueries

citus v8.2.1 (April 03, 2019)

  • Fixes a bug that prevents stack size to be adjusted

citus v8.1.2 (April 03, 2019)

  • Don't do redundant ALTER TABLE consistency checks at coordinator

  • Fixes a bug that prevents stack size to be adjusted

  • Fix an issue with some DECLARE .. CURSOR WITH HOLD commands

citus v8.2.0 (March 28, 2019)

  • Removes support and code for PostgreSQL 9.6

  • Enable more outer joins with reference tables

  • Execute CREATE INDEX CONCURRENTLY in parallel

  • Treat functions as transaction blocks

  • Add support for column aliases on join clauses

  • Skip standard_planner() for trivial queries

  • Added support for function calls in joins

  • Round-robin task assignment policy relies on local transaction id

  • Relax subquery union pushdown restrictions for reference tables

  • Speed-up run_command_on_shards()

  • Address some memory issues in connection config

  • Restrict visibility of get_*activetransactions functions to pg_monitor

  • Don't do redundant ALTER TABLE consistency checks at coordinator

  • Queries with only intermediate results do not rely on task assignment policy

  • Finish connection establishment in parallel for multiple connections

  • Fixes a bug related to pruning shards using a coerced value

  • Fix an issue with some DECLARE .. CURSOR WITH HOLD commands

  • Fixes a bug that could lead to infinite recursion during recursive planning

  • Fixes a bug that could prevent planning full outer joins with using clause

  • Fixes a bug that could lead to memory leak on citus_relation_size

  • Fixes a problem that could cause segmentation fault with recursive planning

  • Switch CI solution to CircleCI

citus v8.0.3 (January 9, 2019)

  • Fixes maintenance daemon panic due to unreleased spinlock

  • Fixes an issue with having clause when used with complex joins

citus v8.1.1 (January 7, 2019)

  • Fixes maintenance daemon panic due to unreleased spinlock

  • Fixes an issue with having clause when used with complex joins

citus v8.1.0 (December 17, 2018)

  • Turns on ssl by default for new installations of citus

  • Restricts SSL Ciphers to TLS1.2 and above

  • Adds support for INSERT INTO SELECT..ON CONFLICT/RETURNING via coordinator

  • Adds support for round-robin task assignment for queries to reference tables

  • Adds support for SQL tasks using worker_execute_sql_task UDF with task-tracker

  • Adds support for VALIDATE CONSTRAINT queries

  • Adds support for disabling hash aggregate with HLL

  • Adds user ID suffix to intermediate files generated by task-tracker

  • Only allow transmit from pgsql_job_cache directory

  • Disallows GROUPING SET clauses in subqueries

  • Removes restriction on user-defined group ID in node addition functions

  • Relaxes multi-shard modify locks when enable_deadlock_prevention is disabled

  • Improves security in task-tracker protocol

  • Improves permission checks in internal DROP TABLE functions

  • Improves permission checks in cluster management functions

  • Cleans up UDFs and fixes permission checks

  • Fixes crashes caused by stack size increase under high memory load

  • Fixes a bug that could cause maintenance daemon panic

citus v8.0.2 (December 13, 2018)

  • Fixes a bug that could cause maintenance daemon panic

  • Fixes crashes caused by stack size increase under high memory load

citus v7.5.4 (December 11, 2018)

  • Fixes a bug that could cause maintenance daemon panic

citus v8.0.1 (November 27, 2018)

  • Execute SQL tasks using worker_execute_sql_task UDF when using task-tracker

citus v7.5.3 (November 27, 2018)

  • Execute SQL tasks using worker_execute_sql_task UDF when using task-tracker

citus v7.5.2 (November 14, 2018)

  • Fixes inconsistent metadata error when shard metadata caching get interrupted

  • Fixes a bug that could cause memory leak

  • Fixes a bug that prevents recovering wrong transactions in MX

  • Fixes a bug to prevent wrong memory accesses on Citus MX under very high load

  • Fixes crashes caused by stack size increase under high memory load

citus v8.0.0 (October 31, 2018)

  • Adds support for PostgreSQL 11

  • Adds support for applying DML operations on reference tables from MX nodes

  • Adds distributed locking to truncated MX tables

  • Adds support for running TRUNCATE command from MX worker nodes

  • Adds views to provide insight about the distributed transactions

  • Adds support for TABLESAMPLE in router queries

  • Adds support for INCLUDE option in index creation

  • Adds option to allow simple DML commands from hot standby

  • Adds support for partitioned tables with replication factor > 1

  • Prevents a deadlock on concurrent DROP TABLE and SELECT on Citus MX

  • Fixes a bug that prevents recovering wrong transactions in MX

  • Fixes a bug to prevent wrong memory accesses on Citus MX under very high load

  • Fixes a bug in MX mode, calling DROP SCHEMA with existing partitioned table

  • Fixes a bug that could cause modifying CTEs to select wrong execution mode

  • Fixes a bug preventing rollback in CREATE PROCEDURE

  • Fixes a bug on not being able to drop index on a partitioned table

  • Fixes a bug on TRUNCATE when there is a foreign key to a reference table

  • Fixes a performance issue in prepared INSERT..SELECT

  • Fixes a bug which causes errors on DROP DATABASE IF EXISTS

  • Fixes a bug to remove intermediate result directory in pull-push execution

  • Improves query pushdown planning performance

  • Evaluate functions anywhere in query

citus v7.5.1 (August 28, 2018)

  • Improves query pushdown planning performance

  • Fixes a bug that could cause modifying CTEs to select wrong execution mode

citus v7.4.2 (July 27, 2018)

  • Fixes a segfault in real-time executor during online shard move

citus v7.5.0 (July 25, 2018)

  • Adds foreign key support from hash distributed to reference tables

  • Adds SELECT ... FOR UPDATE support for router plannable queries

  • Adds support for non-partition columns in count distinct

  • Fixes a segfault in real-time executor during online shard move

  • Fixes ALTER TABLE ADD COLUMN constraint check

  • Fixes a bug where INSERT ... SELECT was allowed to update distribution column

  • Allows DDL commands to be sequentialized via citus.multi_shard_modify_mode

  • Adds support for topn_union_agg and topn_add_agg across shards

  • Adds support for hll_union_agg and hll_add_agg across shards

  • Fixes a bug that might cause shards to have a wrong owner

  • GUC select_opens_transaction_block defers opening transaction block on workers

  • Utils to implement DDLs for policies in future, warn about being unsupported

  • Intermediate results use separate connections to avoid interfering with tasks

  • Adds a node_conninfo GUC to set outgoing connection settings

citus v6.2.6 (July 06, 2018)

  • Adds support for respecting enable_hashagg in the master planner

citus v7.4.1 (June 20, 2018)

  • Fixes a bug that could cause transactions to incorrectly proceed after failure

  • Fixes a bug on INSERT ... SELECT queries in prepared statements

citus v7.4.0 (May 15, 2018)

  • Adds support for non-pushdownable subqueries and CTEs in UPDATE/DELETE queries

  • Adds support for pushdownable subqueries and joins in UPDATE/DELETE queries

  • Adds faster shard pruning for subqueries

  • Adds partitioning support to MX table

  • Adds support for (VACUUM | ANALYZE) VERBOSE

  • Adds support for multiple ANDs in HAVING for pushdown planner

  • Adds support for quotation needy schema names

  • Improves operator check time in physical planner for custom data types

  • Removes broadcast join logic

  • Deprecates large_table_shard_count and master_expire_table_cache()

  • Modifies master_update_node to lock write on shards hosted by node over update

  • DROP TABLE now drops shards as the currrent user instead of the superuser

  • Adds specialised error codes for connection failures

  • Improves error messages on connection failure

  • Fixes issue which prevented multiple citus_table_size calls per query

  • Tests are updated to use create_distributed_table

citus v7.2.2 (May 4, 2018)

  • Fixes a bug that could cause SELECTs to crash during a rebalance

citus v7.3.0 (March 15, 2018)

  • Adds support for non-colocated joins between subqueries

  • Adds support for window functions that can be pushed down to worker

  • Adds support for modifying CTEs

  • Adds recursive plan for subqueries in WHERE clause with recurring FROM clause

  • Adds support for bool_ and bit_ aggregates

  • Adds support for Postgres jsonb and json aggregation functions

  • Adds support for respecting enable_hashagg in the master plan

  • Adds support for renaming a distributed table

  • Adds support for ALTER INDEX (SET|RESET|RENAME TO) commands

  • Adds support for setting storage parameters on distributed tables

  • Performance improvements to reduce distributed planning time

  • Fixes a bug on planner when aggregate is used in ORDER BY

  • Fixes a bug on planner when DISTINCT (ON) clause is used with GROUP BY

  • Fixes a bug of creating coordinator planner with distinct and aggregate clause

  • Fixes a bug that could open a new connection on every table size function call

  • Fixes a bug canceling backends that are not involved in distributed deadlocks

  • Fixes count distinct bug on column expressions when used with subqueries

  • Improves error handling on worker node failures

  • Improves error messages for INSERT queries that have subqueries

citus v7.2.1 (February 6, 2018)

  • Fixes count distinct bug on column expressions when used with subqueries

  • Adds support for respecting enable_hashagg in the master plan

  • Fixes a bug canceling backends that are not involved in distributed deadlocks

citus v7.2.0 (January 16, 2018)

  • Adds support for CTEs

  • Adds support for subqueries that require merge step

  • Adds support for set operations (UNION, INTERSECT, ...)

  • Adds support for 2PC auto-recovery

  • Adds support for querying local tables in CTEs and subqueries

  • Adds support for more SQL coverage in subqueries for reference tables

  • Adds support for count(distinct) in queries with a subquery

  • Adds support for non-equijoins when there is already an equijoin for queries

  • Adds support for non-equijoins when there is already an equijoin for subquery

  • Adds support for real-time executor to run in transaction blocks

  • Adds infrastructure for storing intermediate distributed query results

  • Adds a new GUC named enable_repartition_joins for auto executor switch

  • Adds support for limiting the intermediate result size

  • Improves support for queries with unions containing filters

  • Improves support for queries with unions containing joins

  • Improves support for subqueries in the WHERE clause

  • Increases COPY throughput

  • Enables pushing down queries containing only recurring tuples and GROUP BY

  • Load-balance queries that read from 0 shards

  • Improves support for using functions in subqueries

  • Fixes a bug that could cause real-time executor to crash during cancellation

  • Fixes a bug that could cause real-time executor to get stuck on cancellation

  • Fixes a bug that could block modification queries unnecessarily

  • Fixes a bug that could cause assigning wrong IDs to transactions

  • Fixes a bug that could cause an assert failure with ANALYZE statements

  • Fixes a bug that could allow pushing down wrong set operations in subqueries

  • Fixes a bug that could cause a deadlock in create_distributed_table

  • Fixes a bug that could confuse user about ANALYZE usage

  • Fixes a bug that could lead to false positive distributed deadlock detections

  • Relaxes the locking for DDL commands on partitioned tables

  • Relaxes the locking on COPY with replication

  • Logs more remote commands when citus.log_remote_commands is set

citus v6.2.5 (January 11, 2018)

  • Fixes a bug that could crash the coordinator while reporting a remote error

citus v7.1.2 (January 4, 2018)

  • Fixes a bug that could cause assigning wrong IDs to transactions

  • Increases COPY throughput

citus v7.1.1 (December 1, 2017)

  • Fixes a bug that could prevent pushing down subqueries with reference tables

  • Fixes a bug that could create false positive distributed deadlocks

  • Fixes a bug that could prevent running concurrent COPY and multi-shard DDL

  • Fixes a bug that could mislead users about ANALYZE queries

citus v7.1.0 (November 14, 2017)

  • Adds support for native queries with multi shard UPDATE/DELETE queries

  • Expands reference table support in subquery pushdown

  • Adds window function support for subqueries and INSERT ... SELECT queries

  • Adds support for COUNT(DISTINCT) [ON] queries on non-partition columns

  • Adds support for DISTINCT [ON] queries on non-partition columns

  • Introduces basic usage statistic collector

  • Adds support for setting replica identity while creating distributed tables

  • Adds support for ALTER TABLE ... REPLICA IDENTITY queries

  • Adds pushdown support for LIMIT and HAVING grouped by partition key

  • Adds support for INSERT ... SELECT queries via worker nodes on MX clusters

  • Adds support for adding primary key using already defined index

  • Adds parameter to shard copy functions to support distinct replication models

  • Changes shard_name UDF to omit public schema name

  • Adds master_move_node UDF to make changes on nodename/nodeport more easy

  • Fixes a bug that could cause casting error with INSERT ... SELECT queries

  • Fixes a bug that could prevent upgrading servers from Citus 6.1

  • Fixes a bug that could prevent attaching partitions to a table in schema

  • Fixes a bug that could prevent adding a node to cluster with reference table

  • Fixes a bug that could cause a crash with INSERT ... SELECT queries

  • Fixes a bug that could prevent creating a partitoned table on Cloud

  • Implements various performance improvements

  • Adds internal infrastructures and tests to improve development process

  • Addresses various race conditions and deadlocks

  • Improves and standardizes error messages

citus v7.0.3 (October 16, 2017)

  • Fixes several bugs that could cause crash

  • Fixes a bug that could cause deadlock while creating reference tables

  • Fixes a bug that could cause false-positives in deadlock detection

  • Fixes a bug that could cause 2PC recovery not to work from MX workers

  • Fixes a bug that could cause cache incohorency

  • Fixes a bug that could cause maintenance daemon to skip cache invalidations

  • Improves performance of transaction recovery by using correct index

citus v7.0.2 (September 28, 2017)

  • Updates task-tracker to limit file access

citus v6.2.4 (September 28, 2017)

  • Updates task-tracker to limit file access

citus v6.1.3 (September 28, 2017)

  • Updates task-tracker to limit file access

citus v7.0.1 (September 12, 2017)

  • Fixes a bug that could cause memory leaks in INSERT ... SELECT queries

  • Fixes a bug that could cause incorrect execution of prepared statements

  • Fixes a bug that could cause excessive memory usage during COPY

  • Incorporates latest changes from core PostgreSQL code

citus v7.0.0 (August 28, 2017)

  • Adds support for PostgreSQL 10

  • Drops support for PostgreSQL 9.5

  • Adds support for multi-row INSERT

  • Adds support for router UPDATE and DELETE queries with subqueries

  • Adds infrastructure for distributed deadlock detection

  • Deprecates enable_deadlock_prevention flag

  • Adds support for partitioned tables

  • Adds support for creating UNLOGGED tables

  • Adds support for SAVEPOINT

  • Adds UDF citus_create_restore_point for taking distributed snapshots

  • Adds support for evaluating non-pushable INSERT ... SELECT queries

  • Adds support for subquery pushdown on reference tables

  • Adds shard pruning support for IN and ANY

  • Adds support for UPDATE and DELETE commands that prune down to 0 shard

  • Enhances transaction support by relaxing some transaction restrictions

  • Fixes a bug causing crash if distributed table has no shards

  • Fixes a bug causing crash when removing inactive node

  • Fixes a bug causing failure during COPY on tables with dropped columns

  • Fixes a bug causing failure during DROP EXTENSION

  • Fixes a bug preventing executing VACUUM and INSERT concurrently

  • Fixes a bug in prepared INSERT statements containing an implicit cast

  • Fixes several issues related to statement cancellations and connections

  • Fixes several 2PC related issues

  • Removes an unnecessary dependency causing warning messages in pg_dump

  • Adds internal infrastructure for follower clusters

  • Adds internal infrastructure for progress tracking

  • Implements various performance improvements

  • Adds internal infrastructures and tests to improve development process

  • Addresses various race conditions and deadlocks

  • Improves and standardizes error messages

citus v6.2.3 (July 13, 2017)

  • Fixes a crash during execution of local CREATE INDEX CONCURRENTLY

  • Fixes a bug preventing usage of quoted column names in COPY

  • Fixes a bug in prepared INSERTs with implicit cast in partition column

  • Relaxes locks in VACUUM to ensure concurrent execution with INSERT

citus v6.2.2 (May 31, 2017)

  • Fixes a common cause of deadlocks when repairing tables with foreign keys

citus v6.2.1 (May 24, 2017)

  • Relaxes version-check logic to avoid breaking non-distributed commands

citus v6.2.0 (May 16, 2017)

  • Increases SQL subquery coverage by pushing down more kinds of queries

  • Adds CustomScan API support to allow read-only transactions

  • Adds support for CREATE/DROP INDEX CONCURRENTLY

  • Adds support for ALTER TABLE ... ADD CONSTRAINT

  • Adds support for ALTER TABLE ... RENAME COLUMN

  • Adds support for DISABLE/ENABLE TRIGGER ALL

  • Adds support for expressions in the partition column in INSERTs

  • Adds support for query parameters in combination with function evaluation

  • Adds support for creating distributed tables from non-empty local tables

  • Adds UDFs to get size of distributed tables

  • Adds UDFs to add a new node without replicating reference tables

  • Adds checks to prevent running Citus binaries with wrong metadata tables

  • Improves shard pruning performance for range queries

  • Improves planner performance for joins involving co-located tables

  • Improves shard copy performance by creating indexes after copy

  • Improves task-tracker performance by batching several status checks

  • Enables router planner for queries on range partitioned table

  • Changes TRUNCATE to drop local data only if enable_ddl_propagation is off

  • Starts to execute DDL on coordinator before workers

  • Fixes a bug causing incorrectly reading invalidated cache

  • Fixes a bug related to creation of schemas of in workers with incorrect owner

  • Fixes a bug related to concurrent run of shard drop functions

  • Fixes a bug related to EXPLAIN ANALYZE with DML queries

  • Fixes a bug related to SQL functions in FROM clause

  • Adds a GUC variable to report cross shard queries

  • Fixes a bug related to partition columns without native hash function

  • Adds internal infrastructures and tests to improve development process

  • Addresses various race conditions and deadlocks

  • Improves and standardizes error messages

citus v6.1.2 (May 31, 2017)

  • Fixes a common cause of deadlocks when repairing tables with foreign keys

citus v6.1.1 (May 5, 2017)

  • Fixes a crash caused by router executor use after connection timeouts

  • Fixes a crash caused by relation cache invalidation during COPY

  • Fixes bug related to DDL use within PL/pgSQL functions

  • Fixes a COPY bug related to types lacking binary output functions

  • Fixes a bug related to modifications with parameterized partition values

  • Fixes improper value interpolation in worker sequence generation

  • Guards shard pruning logic against zero-shard tables

  • Fixes possible NULL pointer dereference and buffer underflow (via PVS-Studio)

  • Fixes a INSERT ... SELECT bug that could push down non-partition column JOINs

citus v6.1.0 (February 9, 2017)

  • Implements reference tables, transactionally replicated to all nodes

  • Adds upgrade_to_reference_table UDF to upgrade pre-6.1 reference tables

  • Expands prepared statement support to nearly all statements

  • Adds support for creating VIEWs which reference distributed tables

  • Adds targeted VACUUM/ANALYZE support

  • Adds support for the FILTER clause in aggregate expressions

  • Adds support for function evaluation within INSERT INTO ... SELECT

  • Adds support for creating foreign key constraints with ALTER TABLE

  • Adds logic to choose router planner for all queries it supports

  • Enhances create_distributed_table with parameter for explicit colocation

  • Adds generally useful utility UDFs previously available as "Citus Tools"

  • Adds user-facing UDFs for locking shard resources and metadata

  • Refactors connection and transaction management; giving a consistent experience

  • Enhances COPY with fully transactional semantics

  • Improves support for cancellation for a number of queries and commands

  • Adds column_to_column_name UDF to help users understand partkey values

  • Adds master_disable_node UDF for temporarily disabling nodes

  • Adds proper MX ("masterless") metadata propagation logic

  • Adds start_metadata_sync_to_node UDF to propagate metadata changes to nodes

  • Enhances SERIAL compatibility with MX tables

  • Adds an node_connection_timeout parameter to control node connection timeouts

  • Adds enable_deadlock_prevention setting to permit multi-node transactions

  • Adds a replication_model setting to specify replication of new tables

  • Changes the shard_replication_factor setting's default value to one

  • Adds code to automatically set max_prepared_transactions if not configured

  • Accelerates lookup of colocated shard placements

  • Fixes a bug affecting INSERT INTO ... SELECT queries using constant values

  • Fixes a bug by ensuring COPY does not mark placements inactive

  • Fixes a bug affecting reads from pg_dist_shard_placement table

  • Fixes a crash triggered by creating a foreign key without a column

  • Fixes a crash related to accessing catalog tables after aborted transactions

  • Fixes a bug affecting JOIN queries requiring repartitions

  • Fixes a bug affecting node insertions to pg_dist_node table

  • Fixes a crash triggered by queries with modifying common table expressions

  • Fixes a bug affecting workloads with concurrent shard appends and deletions

  • Addresses various race conditions and deadlocks

  • Improves and standardizes error messages

citus v6.0.1 (November 29, 2016)

  • Fixes a bug causing failures during pg_upgrade

  • Fixes a bug preventing DML queries during colocated table creation

  • Fixes a bug that caused NULL parameters to be incorrectly passed as text

citus v6.0.0 (November 7, 2016)

  • Adds compatibility with PostgreSQL 9.6, now the recommended version

  • Removes the pg_worker_list.conf file in favor of a pg_dist_node table

  • Adds master_add_node and master_add_node UDFs to manage membership

  • Removes the \stage command and corresponding csql binary in favor of COPY

  • Removes copy_to_distributed_table in favor of first-class COPY support

  • Adds support for multiple DDL statements within a transaction

  • Adds support for certain foreign key constraints

  • Adds support for parallel INSERT INTO ... SELECT against colocated tables

  • Adds support for the TRUNCATE command

  • Adds support for HAVING clauses in SELECT queries

  • Adds support for EXCLUDE constraints which include the partition column

  • Adds support for system columns in queries (tableoid, ctid, etc.)

  • Adds support for relation name extension within INDEX definitions

  • Adds support for no-op UPDATEs of the partition column

  • Adds several general-purpose utility UDFs to aid in Citus maintenance

  • Adds master_expire_table_cache UDF to forcibly expire cached shards

  • Parallelizes the processing of DDL commands which affect distributed tables

  • Adds support for repartition jobs using composite or custom types

  • Enhances object name extension to handle long names and large shard counts

  • Parallelizes the master_modify_multiple_shards UDF

  • Changes distributed table creation to error if the target table is not empty

  • Changes the pg_dist_shard.logicalrelid column from an oid to regclass

  • Adds a placementid column to pg_dist_shard_placement, replacing Oid use

  • Removes the pg_dist_shard.shardalias distribution metadata column

  • Adds pg_dist_partition.repmodel to track tables using streaming replication

  • Adds internal infrastructure to take snapshots of distribution metadata

  • Addresses the need to invalidate prepared statements on metadata changes

  • Adds a mark_tables_colocated UDF for denoting pre-6.0 manual colocation

  • Fixes a bug affecting prepared statement execution within PL/pgSQL

  • Fixes a bug affecting COPY commands using composite types

  • Fixes a bug that could cause crashes during EXPLAIN EXECUTE

  • Separates worker and master job temporary folders

  • Eliminates race condition between distributed modification and repair

  • Relaxes the requirement that shard repairs also repair colocated shards

  • Implements internal functions to track which tables' shards are colocated

  • Adds pg_dist_partition.colocationid to track colocation group membership

  • Extends shard copy and move operations to respect colocation settings

  • Adds pg_dist_local_group to prepare for future MX-related changes

  • Adds create_distributed_table to easily create shards and infer colocation

citus v5.2.2 (November 7, 2016)

  • Adds support for IF NOT EXISTS clause of CREATE INDEX command

  • Adds support for RETURN QUERY and FOR ... IN PL/pgSQL features

  • Extends the router planner to handle more queries

  • Changes COUNT of zero-row sets to return 0 rather than an empty result

  • Reduces the minimum permitted task_tracker_delay to a single millisecond

  • Fixes a bug that caused crashes during joins with a WHERE false clause

  • Fixes a bug triggered by unique violation errors raised in long transactions

  • Fixes a bug resulting in multiple registration of transaction callbacks

  • Fixes a bug which could result in stale reads of distribution metadata

  • Fixes a bug preventing distributed modifications in some PL/pgSQL functions

  • Fixes some code paths that could hypothetically read uninitialized memory

  • Lowers log level of waiting for activity messages

citus v5.2.1 (September 6, 2016)

  • Fixes subquery pushdown to properly extract outer join qualifiers

  • Addresses possible memory leak during multi-shard transactions

citus v5.2.0 (August 15, 2016)

  • Drops support for PostgreSQL 9.4; PostgreSQL 9.5 is required

  • Adds schema support for tables, other named objects (types, operators, etc.)

  • Evaluates non-immutable functions on master in all modification commands

  • Adds support for SERIAL types in non-partition columns

  • Adds support for RETURNING clause in INSERT, UPDATE, and DELETE commands

  • Adds support for multi-statement transactions involving a fixed set of nodes

  • Full SQL support for SELECT queries which can be executed on a single worker

  • Adds option to perform DDL changes using prepared transactions (2PC)

  • Adds an enable_ddl_propagation parameter to control DDL propagation

  • Accelerates shard pruning during merges

  • Adds master_modify_multiple_shards UDF to modify many shards at once

  • Adds COPY support for arrays of user-defined types

  • Now supports parameterized prepared statements for certain use cases

  • Extends LIMIT/OFFSET support to all executor types

  • Constraint violations now fail fast rather than hitting all placements

  • Makes master_create_empty_shard aware of shard placement policy

  • Reduces unnecessary sleep during queries processed by real-time executor

  • Improves task tracker executor's task cleanup logic

  • Relaxes restrictions on cancellation of DDL commands

  • Removes ONLY keyword from worker SELECT queries

  • Error message improvements and standardization

  • Moves master_update_shard_statistics function to pg_catalog schema

  • Fixes a bug where hash-partitioned anti-joins could return incorrect results

  • Now sets storage type correctly for foreign table-backed shards

  • Fixes master_update_shard_statistics issue with hash-partitioned tables

  • Fixes an issue related to extending table names that require escaping

  • Reduces risk of row counter overflows during modifications

  • Fixes a crash related to FILTER clause use in COUNT DISTINCT subqueries

  • Fixes crashes related to partition columns with high attribute numbers

  • Fixes certain subquery and join crashes

  • Detects flex for build even if PostgreSQL was built without it

  • Fixes assert-enabled crash when all_modifications_commutative is true

citus v5.2.0-rc.1 (August 1, 2016)

  • Initial 5.2.0 candidate

citus v5.1.1 (June 17, 2016)

  • Adds complex count distinct expression support in repartitioned subqueries

  • Improves task tracker job cleanup logic, addressing a memory leak

  • Fixes bug that generated incorrect results for LEFT JOIN queries

  • Improves compatibility with Debian's reproducible builds project

  • Fixes build issues on FreeBSD platforms

citus v5.1.0 (May 17, 2016)

  • Adds distributed COPY to rapidly populate distributed tables

  • Adds support for using EXPLAIN on distributed queries

  • Recognizes and fast-paths single-shard SELECT statements automatically

  • Increases INSERT throughput via shard pruning optimizations

  • Improves planner performance for joins involving tables with many shards

  • Adds ability to pass columns as arguments to function calls in UPDATEs

  • Introduces transaction manager for use by multi-shard commands

  • Adds COUNT(DISTINCT ...) pushdown optimization for hash-partitioned tables

  • Adds support for certain UNIQUE indexes on hash- or range-partitioned tables

  • Deprecates \stage in favor of using COPY for append-partition tables

  • Deprecates copy_to_distributed_table in favor of first-class COPY support

  • Fixes build problems when using non-packaged PostgreSQL installs

  • Fixes bug that sometimes skipped pruning when partitioned by a VARCHAR column

  • Fixes bug impeding use of user-defined functions in repartitioned subqueries

  • Fixes bug involving queries with equality comparisons of boolean types

  • Fixes crash that prevented use alongside pg_stat_statements

  • Fixes crash arising from SELECT queries that lack a target list

  • Improves warning and error messages

citus v5.1.0-rc.2 (May 10, 2016)

  • Fixes test failures

  • Fixes EXPLAIN output when FORMAT JSON in use

citus v5.1.0-rc.1 (May 4, 2016)

  • Initial 5.1.0 candidate

citus v5.0.1 (April 15, 2016)

  • Fixes issues on 32-bit systems

citus v5.0.0 (March 24, 2016)

  • Public release under AGPLv3

  • PostgreSQL extension compatible with PostgreSQL 9.5 and 9.4