<p style="text-align: center;"><strong><img alt="" src="https://simg.open-open.com/show/2ffa5ffaf48e868f6d963f3155e62d60.png" /></strong></p>    <p> </p>    <p>Citus为PostgreSQL加入了横向扩展和并行查询处理功能，它被云服务公司如CloudFlare用于扩展PostgreSQL，快速分析实时数据。</p>    <p style="text-align: center;"><a href="https://simg.open-open.com/show/ed4f132041cc64aab7b99dc518262054.gif"><img alt="" src="https://simg.open-open.com/show/ed4f132041cc64aab7b99dc518262054.gif" /></a></p>    <h2>更新日志</h2>    <ul>     <li>Implements <em>reference tables</em>, transactionally replicated to all nodes</li>     <li>Adds <code>upgrade_to_reference_table</code> UDF to upgrade pre-6.1 reference tables</li>     <li>Expands prepared statement support to nearly all statements</li>     <li>Adds support for creating <code>VIEW</code>s which reference distributed tables</li>     <li>Adds targeted <code>VACUUM</code>/<code>ANALYZE</code> support</li>     <li>Adds support for the <code>FILTER</code> clause in aggregate expressions</li>     <li>Adds support for function evaluation within <code>INSERT INTO ... SELECT</code></li>     <li>Adds support for creating foreign key constraints with <code>ALTER TABLE</code></li>     <li>Adds logic to choose router planner for all queries it supports</li>     <li>Enhances <code>create_distributed_table</code> with parameter for explicit colocation</li>     <li>Adds generally useful utility UDFs previously available as "Citus Tools"</li>     <li>Adds user-facing UDFs for locking shard resources and metadata</li>     <li>Refactors connection and transaction management; giving a consistent experience</li>     <li>Enhances <code>COPY</code> with fully transactional semantics</li>     <li>Improves support for cancellation for a number of queries and commands</li>     <li>Adds <code>column_to_column_name</code> UDF to help users understand <code>partkey</code> values</li>     <li>Adds <code>master_disable_node</code> UDF for temporarily disabling nodes</li>     <li>Adds proper MX ("masterless") metadata propagation logic</li>     <li>Adds <code>start_metadata_sync_to_node</code> UDF to propagate metadata changes to nodes</li>     <li>Enhances <code>SERIAL</code> compatibility with MX tables</li>     <li>Adds an <code>node_connection_timeout</code> parameter to control node connection timeouts</li>     <li>Adds <code>enable_deadlock_prevention</code> setting to permit multi-node transactions</li>     <li>Adds a <code>replication_model</code> setting to specify replication of new tables</li>     <li>Changes the <code>shard_replication_factor</code> setting's default value to one</li>     <li>Adds code to automatically set <code>max_prepared_transactions</code> if not configured</li>     <li>Accelerates lookup of colocated shard placements</li>     <li>Fixes a bug affecting <code>INSERT INTO ... SELECT</code> queries using constant values</li>     <li>Fixes a bug by ensuring <code>COPY</code> does not mark placements inactive</li>     <li>Fixes a bug affecting reads from <code>pg_dist_shard_placement</code> table</li>     <li>Fixes a crash triggered by creating a foreign key without a column</li>     <li>Fixes a crash related to accessing catalog tables after aborted transactions</li>     <li>Fixes a bug affecting JOIN queries requiring repartitions</li>     <li>Fixes a bug affecting node insertions to <code>pg_dist_node</code> table</li>     <li>Fixes a crash triggered by queries with modifying common table expressions</li>     <li>Fixes a bug affecting workloads with concurrent shard appends and deletions</li>     <li>Addresses various race conditions and deadlocks</li>     <li>Improves and standardizes error messages</li>    </ul>    <h2>下载</h2>    <ul>     <li><a href="/misc/goto?guid=4958999371215099614" rel="nofollow"><strong>Source code</strong> (zip)</a></li>     <li><a href="/misc/goto?guid=4958999371322548734" rel="nofollow"><strong>Source code</strong> (tar.gz)</a></li>    </ul>    <p>本站原创，转载时保留以下信息：<br /> 本文转自：深度开源（open-open.com）<br /> 原文地址：<a href="http://www.open-open.com/news/view/163e4f05">http://www.open-open.com/news/view/163e4f05</a></p>