相关疑难解决方法(0)

如果您想生成时间序列，请参阅此问题

假设我想在两个日期之间生成一系列日期。我看到该功能generate_series仅提供

Function                                    Argument Type                         Return Type                                                               Description
generate_series(start, stop, step interval) timestamp or timestamp with time zone setof timestamp or setof timestamp with time zone (same as argument type) Generate a series of values, from start to stop with a step size of step

那么我该怎么做呢？

我使用的是 PostgreSQL V9.6.11

表DDL：

CREATE TABLE test_c ( 
          insrt_prcs_id bigint NOT NULL, 
          updt_prcs_id bigint, src_sys_id integer NOT NULL,
          load_dttm timestamp(6) with time zone NOT NULL, 
          updt_dttm timestamp(6) without time zone);

我试图index为下面的查询创建一个：

SELECT * 
FROM test_c             
WHERE COALESCE(u_dttm,l_dttm) > '2020-04-10 15:29:44.596311-07'
AND   COALESCE(u_dttm,l_dttm) <= '2020-04-11 15:29:44.596311-07' 

创建index为：

create index idx_test_c  on test_c(COALESCE((updt_dttm, load_dttm)))

但查询计划器没有扫描索引：

EXPLAIN ANALYZE
SELECT *            
FROM test_c             
WHERE COALESCE(u_dttm,l_dttm) > '2020-04-10 15:29:44.596311-07'
AND   COALESCE(u_dttm,l_dttm) <= '2020-04-11 15:29:44.596311-07' 

Seq Scan on test_c as test_c (cost=0..1857.08 …