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PostgreSQL??? ??? ?? ??? ?? ?? ?? ?? ???? ? ?? ??? ? ????. ? ??? ???? ?.
? ???? RANGE ??(Postgres 11 ?? ??)
Postgres 11 ??? ?? RANGE ??? ???? PRECEDING ? EXCLUDE ??? ???? ?? ??? ??? ? ????.
SELECT id, ts , count(*) OVER (ORDER BY ts RANGE '1 hour' PRECEDING EXCLUDE CURRENT ROW) FROM test ORDER BY ts;
?? PostgreSQL ??
?? ??? PostgreSQL? ?? ?? ?? ??? ??? ????. ?? ??:
Roman's Query(ROM)
SELECT id, ts , (SELECT count(*)::int - 1 FROM unnest(dates) x WHERE x >= sub.ts - interval '1h') AS ct FROM ( SELECT id, ts , array_agg(ts) OVER (ORDER BY ts) AS dates FROM test ) sub;
?? ??(ARR)
SELECT id, ts , (SELECT count(*) FROM test t1 WHERE t1.ts >= t.ts - interval '1h' AND t1.ts < t.ts) AS ct FROM test t ORDER BY ts;
PL/pgSQL ?? (FNC)
CREATE OR REPLACE FUNCTION running_window_ct(_intv interval = '1 hour') RETURNS TABLE (id bigint, ts timestamp, ct int) AS $func$ DECLARE cur CURSOR FOR SELECT t.ts + _intv AS ts1 , row_number() OVER (ORDER BY t.ts ROWS UNBOUNDED PRECEDING) AS rn FROM test t ORDER BY t.ts; rec record; rn int; BEGIN OPEN cur; FETCH cur INTO rec; ct := -1; FOR id, ts, rn IN SELECT t.id, t.ts, row_number() OVER (ORDER BY t.ts ROWS UNBOUNDED PRECEDING) FROM test t ORDER BY t.ts LOOP IF rec.ts1 >= ts THEN ct := ct + 1; ELSE LOOP FETCH cur INTO rec; EXIT WHEN rec.ts1 >= ts; END LOOP; ct := rn - rec.rn; END IF; RETURN NEXT; END LOOP; END $func$;
??? ?? ???? ?? ??:
SELECT * FROM running_window_ct('1 hour');? ??? PostgreSQL?? ?? ?? ??? ?? ?? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!
? AI ??
Undress AI Tool
??? ???? ??
Undresser.AI Undress
???? ?? ??? ??? ?? AI ?? ?
AI Clothes Remover
???? ?? ???? ??? AI ?????.
Clothoff.io
AI ? ???
Video Face Swap
??? ??? AI ?? ?? ??? ???? ?? ???? ??? ?? ????!
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???++7.3.1
???? ?? ?? ?? ???
SublimeText3 ??? ??
??? ??, ???? ?? ????.
???? 13.0.1 ???
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???? CS6
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SublimeText3 Mac ??
? ??? ?? ?? ?????(SublimeText3)
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GTID (Global Transaction Identifier) ??? ???? ??? ??????
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GTID (Global Transaction Identifier)? ? ????? ?? ? ??? ???? MySQL ???????? ?? ? ?? ??? ???? ?????. 1. ?? ??? ????? ?? ?? ? ??? ???? ???? ???? ??? ????? ?? ? GTID? ???? ????? ??? ? ????. 2. ?? ?? ???? ???? ? ????? ? ???? ? ?? ??????? ??? ???? ?????. 3. ?? ?? ???? ??????. GTID?? ?? UUID ? ?? ??? ???? ??? ???? ??? ???? ? ???? ??? ???? ????. ? ? ?? ?? ??? MySQL ????? ???? ???? ???? ??? ???? ??? ???? ?? ??????.
MySQL ??? ?? ??? ???? ????? ??????
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MySQL ?? ????? ?? ???? ?? 4 ??? ?????. 1. ?? ?? : ????? ? ????? ????, ?? ?? ? ??? ??? ????? ???? ?? ???? ??? ???? ?? ??? ??? ?? ? ?? ????? ???? MHA, ???????? ?? ??? ??? ? ??? ??? ??? ? ????. 2. ? ?? ?????? ?????? : ??? ??? ?? ?? (Seconds_Behind_master), Binlog ??? ???, ???? ?? ??? ??? ?? ?? ??? ???? ?????? ???? ??? ?? ??? ?? ?? ?? ??? ??????. 3. Switch Topology : ?? ???? ?????? ??? ??? ?????? ???, ?? ???? ????? GTID? ????? VIP, DNS ?? ??? ??? ????????.
?? ?? ???? MySQL ??????? ???? ??? ??????
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MySQL ??????? ???? ??? ??? ????. 1. ?? ?? ??? ???? MySQL-U ??? ?? -P-H ??? ??? ????? ??? ??? ????? ???? ???????. 2. ??? ??????? ?? ?? ???? ?? MySQL-Uroot-PmyProject? ?? ?? ? ?????? ??? ?? ? ? ????. 3. ??? ?? 3306? ?? ?? MySQL-Uroot-P-H192.168.1.100-P3307? ?? ?? ??? ????? -p ?? ??? ???????. ?? ???? ??? ???? ?? ?? ? ? ????. ??? ???? ????, ??? ?? ?? ??? ??????. ?????? ?? ? ?? ??? ???? ?? Linux? MySQL-Client? ??? ? ????. ? ??? ???????
MySQL ? ????? ??? ??? ???? ??
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MySQL? ? ????? ??? ??? ????? ?? ?? ??? ?? ???????. 1. Windows ??? : MySQL ?? ?????? ? ??? ????? (?? ??? ????? C : \ programfiles \ mysql \ mysqlserverx.x \ bin), "? ???"→ "??"→ "Advanced System ??"→ "?? ??", "??? ??", MySQlb in wors in mysqlb in wors in mysqlb in world in that the the the the the seel worl ?? ????? ?? ???? MySQL? ??????-Version Versification; 2.Macos ? Linux ??? : Bash ??? ?? ~/.bashrc ?? ~/.bash_
MySQL? ???? ?? ??? ???? ?? ???? ?????
Jun 23, 2025 pm 03:05 PM
MySQL? ?? ???? ?? ??? ??? ? A??, ?? MVCC ? GAP ?? ??? ?? ??? ?? ? ?? ???? ??? ???? ???? ?? ?? ??? ????. ?? ?? ??? ??? ?? (??)? ????? ??? ??? ????? ?? ?? ??? ????? 1. ??? ??? (read committed)? ?? ? ???? ?? ? ??? ?? ? ??? ?? ? ?? ?? ?? ?? ? ? ????. ???, ??? ??? ????? ??? ??;
MySQL ????? ?? ??? ??????
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MySQL ????? ?? ??? ?? ?????? ????? ???? ???? ?????. ??, ???? ??? ???? ??? ????? ?????. ?? ?? ?? ?? ??? ?????. ?? ??, ?? ? ??? ?? ???? ??? ????? ??? ???? ??????. ??, ???? ????? ??????? ? ??? ???? ?? ??? ?? ? ? ????? ?? ?? ? ???? ?? ????? ?? ??? ??? ??? ?????. ??, ??? ?? ??? ?? ??? ???? ????, ??? ??, ?? ???? ?? ? ??? ??? ?????. MySQL? readuncommitted ? readcommi? ?????.
???? MySQL ?? ??? ????? ??? ??????
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INdexESINMYSQLIMPROVEQUERYPEEDBYENABLEABERDATARETRIVEAL.1. THEYREDUCEDASCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCANCEND, WHERREORORDERBANTROWESINTROWSES, ?? ?? ??? ???? ?????
MySQL Workbench? ?? ??? ??? ??????
Jun 26, 2025 am 05:23 AM
mysqlworkbench? ??? ?? ??? ?? ??? ?????. ?? ??? ?? ??? ?? ????. 1. Windows ???? %appdata %\ mysql \ workbench \ connections.xml? ????. 2. MacOS ???? ~/Library/ApplicationSupport/MySQL/Workbench/Connections.xml? ????. 3. ????? Linux ???? ~/.mysql/workbench/connections.xml ?? ~/.local/share/data/mysql/wor? ????.
