数据仓库服务 GAUSSDB(DWS)-字典编码的hint:示例

时间:2024-12-09 15:13:23

示例

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SELECT /*+ dict (bitmaptbl_high (server_ip)) */ distinct(server_ip) FROM bitmaptbl_high WHERE scope_name='saetataetaeta' ORDER BY server_ip;

生成的计划如下,server_ip使用了字典编码:

使用no dict可以禁用server_ip使用字典编码:

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SELECT /*+ no dict (bitmaptbl_high (server_ip)) */ distinct(server_ip) FROM bitmaptbl_high WHERE scope_name='saetataetaeta' ORDER BY server_ip;
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