CHANGELOG.md

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 v6.1.1 (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