在使用 PostgreSQL 的 indexof 函数时,有以下一些注意事项: indexof 函数用于在字符串中查找子字符串的起始位置,但是它不会返回所有匹配的位置,而只返回第一个匹配的位置。 indexof 函数的语法为 indexof(string, substring),其中 string 是要搜索的字符串,substring 是要查找的子字符串。 indexof 函数区分大小写...
test=# \dA+List of access methodsName | Type | Handler | Description---+---+---+---brin | Index | brinhandler | block range index (BRIN) access methodbtree | Index | bthandler | b-tree index access methodgin | Index | ginhandler | GIN index access methodgist | Index | gisthan...
ALTERDEFAULTPRIVILEGES[FOR{ROLE|USER}target_role[,...]][INSCHEMAschema_name[,...]]abbreviated_grant_or_revoke where abbreviated_grant_or_revoke is oneof:GRANT{{SELECT|INSERT|UPDATE|DELETE|TRUNCATE|REFERENCES|TRIGGER}[,...]|ALL[PRIVILEGES]}ONTABLESTO{[GROUP]role_name|PUBLIC}[,...][WITHGRAN...
_option_index", ERRCODE_FDW_INVALID_OPTION_INDEX }, { "fdw_invalid_option_name", ERRCODE_FDW_INVALID_OPTION_NAME }, { "fdw_invalid_string_length_or_buffer_length", ERRCODE_FDW_INVALID_STRING_LENGTH_OR_BUFFER_LENGTH }, { "fdw_invalid_string_format", ERRCODE_FDW_INVALID_STRING_FORMAT },...
Will need to shape table */ Node *larg; /* left subtree */ Node *rarg; /* right subtree */ List *usingClause; /* USING clause, if any (list of String) */ Node *quals; /* qualifiers on join, if any */ Alias *alias; /* user-written alias clause, if any */ int rtindex;...
create index idx_remark_gin on nb_app_adm_per_base_s using gin (replace(array_to_string_immutable(remark,','),',','') gin_trgm_ops); 12. 查询表数据量 select relname,reltuples::bigint from pg_class where relkind = 'r' and relnamespace=(select oid from pg_namespace where nspna...
2 关于表中的INDEX 的命中率 SELECT relname, CASE idx_scan WHEN 0 THEN NULL ELSE round(100.0 * idx_scan / (seq_scan + idx_scan), 5) END percent_of_times_index_used, n_live_tup rows_in_table FROM pg_stat_user_tables ORDER BY ...
string_agg---53d3ec7adbeacc912a45bdd8557b435be848e4b1050dc0f5e46b75703d4745833541b5dabc177db460b6b1493961fc72c478daaaac74bcc89aec4f946a496028d9cff1cc4144f738e01ea36436455c216aa697d87fe1f87ceb49134a687dc69cba34c9951d0c9ce9ca82bba229d56874af40498dca5f d8dfb9c877546db76c35a3362d6bdba...
/* left subtree */ Node *rarg; /* right subtree */ List *usingClause; /* USING clause, if any (list of String) */ Node *quals; /* qualifiers on join, if any */ Alias *alias; /* user-written alias clause, if any */ int rtindex; /* RT index assigned for join, or 0 */...
geqo_copy(root, momma, &pool->data[first], pool->string_length); geqo_copy(root, daddy, &pool->data[second], pool->string_length); } 线性随机 static int linear_rand(PlannerInfo *root, int pool_size, double bias) { double index; /* index between 0 and pool_size */ ...