从我的debug 看 steps 的最后一个step 会进入类似 EEO_CASE(EEOP_ASSIGN_TMP_MAKE_RO)逻辑, 整个表达式最后的结果 被存入到 resultslot. tts_value 的赋值在这个代码段完成下面的CallStack 就是针对简单查询的表达式调用 SELECT convert_from(BYTEA '\x43d4544520442749564f495245', 'latin-1'); ...
#log_directory = 'log' # directory where log files are written, # can be absolute or relative to PGDATA# 日志保留一天,每个小时一个文件取决于log_rotation_age 每小时切换一下 #log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' # log file name pattern, # can include strftime() escapes#...
select sum(vcount) into fcount from A where 如果A表中不存在bid="xxxxxx"的记录,则fcount=null(即使fcount定义时设置了默认值,如:fcount number(8):=0依然无效,fcount还是会变成null),这样以后使用fcount时就可能有问题,所以在这里最好先判断一下: if fcount is null then fcount:=0; end if; 这...
postgres=# create table test1(id int8, info text, crt_time timestamp); CREATE TABLE Time: 12.851 ms postgres=# create index idx_test1_id on test1(id); CREATE INDEX Time: 9.513 ms 建表 postgres=# do language plpgsql $$ declare i int; begin for i in 1..1000 loop execute 'create t...
11 Optimizing concurrent updates in Postgres 9 Postgres ERROR: tuple concurrently updated 4 Update nth element of array using a WHERE clause See more linked questions Related 3 Postgres synchronized backup - what's with the archive? 0 How to limit the range of an insert-update to only...
transformWhereClause:上面的where子句是一个A_expr,kind为AEXPR_OP看一下是如何进行语义分析的。transformWhereClause-->transformExpr-->transformExprRecurse-->transformAExprOp static Node *transformAExprOp(ParseState *pstate, A_Expr *a) { ... { /* Ordinary scalar operator */ Node *last_srf = p...
When you have that, you could use the is_json function in a CASE or WHERE clause to narrow down the valid values. -- this can eliminate invalid values SELECT user_data::json #> '{user,name}' FROM users WHERE is_json(user_data); -- or this if you want to fill ...
pg_user uWHEREt.tablename=t_nameORDERBYu.usename; $function$ I don't love that function...but I don't hate it enough that I ever get around to rewriting it. (The bits I hate are my fault, not whoever I adapted it from.) If I were to rewrite it, I'd get rid of the uppe...
Re: Use ctid in where clause in update from statement From Dirk Mika Date: 01 July 2019, 14:18:33 Hi, The problem with the INSERT ON CONFLICT is that an insert is tried here first, which may fire triggers. In my case there is a fairly expensive INSERT Trigger ON EACH ROW, which ...
Where:Where clause is used to specify a column from which we use like query condition in PostgreSQL. Where clause is very important while using like query in PostgreSQL. Like:We can use the like query in PostgreSQL to retrieve the data from the table while matching the text pattern using th...