1. Cascade框架SQL优化器新一代cascade框架的SQL优化器，面向全并行执行架构，代价优化CBO和规则优化RBO相结合，实现复杂SQL免调优。 cascade框架的SQL优化器具备以下功能： • Top-Down路径搜索框架，搜索和路径选择更全面精准，避免出现局部查询路径最优解；• 子查询自动改写为分布式JOIN，实现并行计算，规避手工改写调优；•....

文章 2023-05-22 来自：开发者社区

《阿里云认证的解析与实战-数据仓库ACP认证》——云原生数据仓库AnalyticDB PostgreSQL版解析与实践（下）——三、SQL性能调优（下）

更多精彩内容，欢迎观看：：《阿里云认证的解析与实战-数据仓库ACP认证》——云原生数据仓库AnalyticDB PostgreSQL版解析与实践（下）——三、SQL性能调优（下）：6. 可视化执行计划如图是执行计划可视化展示。示例语句explain （format json,analyze true） select count(*) from test,tes....

文章 2023-05-22 来自：开发者社区

《阿里云认证的解析与实战-数据仓库ACP认证》——云原生数据仓库AnalyticDB PostgreSQL版功能演示（上）——五、执行SQL查询

查询customer表的总行数。查询语句如下：SELECT count() FROM customer;

文章 2023-05-22 来自：开发者社区

《阿里云认证的解析与实战-数据仓库ACP认证》——云原生数据仓库AnalyticDB PostgreSQL版功能演示（上）——七、常用运维SQL

1. 检查实例的可用性 • 在master节点上执行语句：select now(); • 在所有节点上执行语句：select now() from gp_dist_random('gp_id'); 如果返回失败则不可用。 2. 查看当前运行的SQLselect * from pg_stat_activity where query != '<IDLE....

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