摘要：The email lists: may be a buffer overflow problem [ecpg bug]: can not use single '*' in multi-line comment after c preprocessor directives
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posted @ 2024-09-26 10:39
随笔分类 - database / postgresql
摘要：(classid,objid,objsubid) depends on (refclassid,refobjid,refobjsubid). -- which objects does relation 88088 depends on select * from pg_depend where c
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posted @ 2024-08-15 21:22
摘要：How does sig_atomic_t actually work? Key Takeways: sig_atomic_t is not an atomic data type used in the context of a signal handler An integral type th
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posted @ 2024-08-13 10:45
摘要：kinds of frame definition implementation https://ldd.cool/pdf/windowagg.pdf
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posted @ 2024-08-10 20:56
摘要：From comments of struct JunkFilter: A junk attribute is an attribute in a tuple that is needed only for storing intermediate information in the execut
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posted @ 2024-07-26 17:27
摘要：https://www.postgresql.eu/events/pgconfeu2017/schedule/session/1585-be-pro-activ-on-postgresql-performance/ https://www.postgresql.eu/events/pgconfeu2
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posted @ 2024-07-20 03:38
摘要：What NamedTuplestore 按字面意思理解，就是一个有名字的 tuplestore, 那估计就不是一个正常的表。根据 PostgreSQL 的官方叫法，NamedTuplestoreScan 对应的表称为 Ephemeral Named Relation， 中文翻译为 短暂的命名关系.
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posted @ 2024-07-08 09:51
摘要：One sentence summary A temporary table could reside within a temporary tablespace, utilizing a temporary name in a temporary schema or namespace. More
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posted @ 2024-06-28 16:39
摘要：The following sql statements will trigger calling function GetExistingLocalJoinPath. setup CREATE EXTENSION postgres_fdw; CREATE SERVER foreign_server
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posted @ 2024-05-29 20:03
摘要：The SQL select sum(sum(a)) from myt1 group by a; This note focuses only on sum(sum(a)) and it's about how postgres rejects the sql above. Notes sum(su
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posted @ 2024-05-11 20:25
摘要：This note will introduce the workflow of parse.pl of the ecpg precompiler. Run the precompiler: perl parse.pl . ../../../backend/parser/gram.y workflo
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posted @ 2024-04-19 11:35
摘要：The SQL select a from (select a from t); Overview from (select a from t) will map to one RangeTblEntry struct of the outter query. from t will map to
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posted @ 2024-04-11 16:09
摘要：SQL CREATE TABLE measurement ( city_id int not null, logdate date not null, data text ) PARTITION BY RANGE (logdate); CREATE TABLE p1 PARTITION OF mea
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posted @ 2024-03-26 00:33
摘要：Overview In this article, I will inspect the postgresql code to find out the implementation of alter table command, specifically, the add column subco
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posted @ 2024-03-23 18:37
摘要：The SQL select xmin::text::int8; grammar a_expr: a_expr TYPECAST Typename { $$ = makeTypeCast($1, $3, @2); } static Node * makeTypeCast(Node *arg, Typ
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posted @ 2024-03-08 09:20
摘要：
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posted @ 2024-02-29 20:44
摘要：based on postgres commit b96115acb8a0e08a46877c2b8ef2a7b5560b371b The SQL CREATE OR REPLACE FUNCTION demo_fors() RETURNS VOID AS $$ DECLARE a RECORD;
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posted @ 2024-02-06 12:10
摘要：postgre version 17(commit hash: a17aa50d67bad4ee39a94988c679d2c2fed0e934) The SQL CREATE FUNCTION process_orders() RETURNS void AS $$ DECLARE c record
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posted @ 2024-01-30 20:06
摘要：what is ‘query jumbling’? SUMMARY: it’s a mechanism for calculating query id. DETAIL: PostgreSQL extracts the node->type of each Node in the raw query
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posted @ 2024-01-12 11:23
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