2018年PostgreSQL中国技术大会 为什么我们抛弃MongoDB和 MySQL，选择PgSQL 张启程 qc@aochuang.cn 奥创软件研究院（上海）研发中心 2018年PostgreSQL中国技术大会 任何数据库都很好用 • 我不是一个专业的DBA ，对数据库的理解不够深入，也不 一定准确，在此抛砖引玉，只是结合我们团队业务场景来 分享下我们选择数据库的过程。 • 2018年PostgreSQL中国技术大会 MySQL应用史 • 最开始做的站群系统WEB端使用MySQL： • copy简单快速，批量复制，替换修改简单； • 每个网站一个库，单体数据量小，数据类型固定； • 后来做SCRM系统，也首选MySQL： • 需求经常改动，每次改需求先改数据库； • 数据量越来越大，越来越不了解这只海豚； 2018年PostgreSQL中国技术大会 MySQL+MongoDB • • 迫于无奈，分拆数据，将需要用到事务、调用频繁的数据 继续用MySQL,将IM中聊天记录等数据量大的数据，用 MongoDB存储，减轻MySQL负担； • 这种方式虽然可以暂时解决问题，我们自己用也没有任何 问题，可以结合各自数据库优点，发挥性能。但是我们有 很多客户是需要私有化部署数据库，让每家客户都接受这 种方式，会为甲方增加很多服务器以及运维成本，可能客 户数据量很少，也需要使用双数据库，更新运维都比较麻

2016 中国用户大会 Solutions – Postgres-XL • Scale-out RDBMS • MPP for OLAP • OLTP write and read scalability • Custer-wide ACID properties • Can also act as distributed key-value store • Currently No distributed consistency Postgres-XL can do all of the above It may be difficult to build a scalability solution relying on postgres_fdw, unless schema can be partitioned in such a way to avoid distributed

significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The contrib/dbmirror improvements (Steven Singer) • New contrib/xml2 (John Gray, Torchbox) • Updated contrib/mysql • New version of contrib/btree_gist (Teodor) • New contrib/trgm, trigram matching for PostgreSQL pgcrypto (Marko Kreen) • Prevent crash in xml (John Gray, Michael Richards) • Update oracle • Update mysql • Update cube (Bruno Wolff III) • Update earthdistance to use cube (Bruno Wolff III) • Update btree_gist

significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The contrib/dbmirror improvements (Steven Singer) • New contrib/xml2 (John Gray, Torchbox) • Updated contrib/mysql • New version of contrib/btree_gist (Teodor) • New contrib/trgm, trigram matching for PostgreSQL pgcrypto (Marko Kreen) • Prevent crash in xml (John Gray, Michael Richards) • Update oracle • Update mysql • Update cube (Bruno Wolff III) • Update earthdistance to use cube (Bruno Wolff III) • Update btree_gist

significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The contrib/dbmirror improvements (Steven Singer) • New contrib/xml2 (John Gray, Torchbox) • Updated contrib/mysql • New version of contrib/btree_gist (Teodor) • New contrib/trgm, trigram matching for PostgreSQL pgcrypto (Marko Kreen) • Prevent crash in xml (John Gray, Michael Richards) • Update oracle • Update mysql • Update cube (Bruno Wolff III) • Update earthdistance to use cube (Bruno Wolff III) • Update btree_gist

significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The contrib/dbmirror improvements (Steven Singer) • New contrib/xml2 (John Gray, Torchbox) • Updated contrib/mysql • New version of contrib/btree_gist (Teodor) • New contrib/trgm, trigram matching for PostgreSQL pgcrypto (Marko Kreen) • Prevent crash in xml (John Gray, Michael Richards) • Update oracle • Update mysql • Update cube (Bruno Wolff III) • Update earthdistance to use cube (Bruno Wolff III) • Update btree_gist

certificate can be used for testing, a certificate signed by a certificate authority (CA) (usually an enterprise-wide root CA) should be used in production. To create a server certificate whose identity can above. LIMIT and OFFSET The clauses LIMIT and OFFSET are PostgreSQL-specific syntax, also used by MySQL. The SQL:2008 standard has introduced the clauses OFFSET ... FETCH {FIRST|NEXT} ... for the same functionality useful and low-administration form of replication, either for high availability or for horizontal scalability. • Allow a standby server to accept read-only queries (Simon Riggs, Heikki Linnakangas) This

certificate can be used for testing, a certificate signed by a certificate authority (CA) (usually an enterprise-wide root CA) should be used in production. To create a server certificate whose identity can SELECT LIMIT and OFFSET The clauses LIMIT and OFFSET are PostgreSQL-specific syntax, also used by MySQL. The SQL:2008 standard has introduced the clauses OFFSET ... FETCH {FIRST|NEXT} ... for the same functional- useful and low-administration form of replication, either for high availability or for horizontal scalability. • Allow a standby server to accept read-only queries (Simon Riggs, Heikki Linnakangas) This

above. LIMIT and OFFSET The clauses LIMIT and OFFSET are PostgreSQL-specific syntax, also used by MySQL. The SQL:2008 standard has introduced the clauses OFFSET ... FETCH {FIRST|NEXT} ... for the same functional- useful and low-administration form of replication, either for high availability or for horizontal scalability. • Allow a standby server to accept read-only queries (Simon Riggs, Heikki Linnakangas) This significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The

above. LIMIT and OFFSET The clauses LIMIT and OFFSET are PostgreSQL-specific syntax, also used by MySQL. The SQL:2008 standard has introduced the clauses OFFSET ... FETCH {FIRST|NEXT} ... for the same functionality useful and low-administration form of replication, either for high availability or for horizontal scalability. • Allow a standby server to accept read-only queries (Simon Riggs, Heikki Linnakangas) This significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The