Tso tawm DBMS SQLite 3.32. Qhov project DuckDB tsim ib qho txawv ntawm SQLite rau kev txheeb xyuas cov lus nug

luam tawm tso tawm SQLite 3.32.0, ib lub teeb DBMS tsim los ua lub tsev qiv ntawv plug-in. SQLite code yog faib raws li pej xeem sau, i.e. tuaj yeem siv yam tsis muaj kev txwv thiab pub dawb rau txhua lub hom phiaj. Kev them nyiaj yug rau SQLite developers yog muab los ntawm ib tug tshwj xeeb tsim consortium, uas muaj xws li cov tuam txhab xws li Adobe, Oracle, Mozilla, Bentley thiab Bloomberg.

ntsiab hloov:

• Ua tiav kwv yees ib qho kev sib txawv ntawm ANALYZE hais kom ua, uas tso cai rau koj los ntawm kev sau ib nrab ntawm cov txheeb cais hauv cov ntaub ntawv loj heev, tsis muaj kev ntsuas tag nrho ntawm indexes. Qhov txwv ntawm tus naj npawb ntawm cov ntaub ntawv thaum luam theej duab ib qhov ntsuas tau teeb tsa siv cov lus qhia tshiab "PRAGMA analysis_limit".
• Ntxiv tshiab virtual rooj "bytecode", uas muaj cov ntaub ntawv hais txog bytecode pre-npaj kab lus (npaj cov lus).
• Ntxiv VFS txheej checksum, uas ntxiv 8-byte checksums mus rau qhov kawg ntawm txhua nplooj ntawv ntawm cov ntaub ntawv hauv cov ntaub ntawv thiab xyuas lawv txhua zaus nws tau nyeem los ntawm cov ntaub ntawv. Cov txheej tso cai rau koj los txheeb xyuas qhov kev puas tsuaj ntawm cov ntaub ntawv raws li qhov tshwm sim ntawm kev tsis ncaj ncees ntawm cov khoom hauv cov khoom siv cia.
• Ntxiv tshiab SQL muaj nuj nqi iif(X,Y,Z), rov qab tus nqi Y yog hais tias X muaj tseeb, lossis Z lwm yam.
• INSERT thiab UPDATE cov kab lus tam sim no ib txwm muaj siv rau freezing kab hom (kab affinity) ua ntej ntsuas cov xwm txheej hauv qhov thaiv KOS.
• Qhov txwv ntawm tus naj npawb ntawm cov tsis tau nce los ntawm 999 mus rau 32766.
• Ntxiv txuas ntxiv UINT collating sequence nrog rau kev siv cov kab ke sorting uas coj mus rau hauv tus account cov lej hauv cov ntawv nyeem kom txheeb cov ntawv ntawd hauv cov lej.
• Hauv kab hais kom ua interface, cov kev xaiv "-csv", "-ascii" thiab "-skip" tau ntxiv rau ".import" hais kom ua. Cov lus txib ".dump" tso cai rau kev siv ntau yam LIKE templates nrog cov khoom tso tawm ntawm txhua lub rooj sib txuas rau lub qhov ncauj qhov ntswg. Ntxiv ".oom" hais kom ua rau kev debug tsim. Ntxiv "--bom" kev xaiv rau ".excel", ".output" thiab ".onece" commands. Ntxiv "--schema" kev xaiv rau ".fillectrl" hais kom ua.
• Cov lus ESCAPE tau teev tseg nrog tus neeg siv LIKE tam sim no overrides wildcards, raws li PostgreSQL tus cwj pwm.

Tsis tas li ntawd, peb tuaj yeem nco txog kev txhim kho DBMS tshiab DuckDB, uas tab tom txhim kho qhov sib txawv ntawm SQLite optimized rau kev ua tiav analytical queries.
Ntxiv nrog rau lub plhaub code los ntawm SQLite, qhov project siv cov parser los ntawm PostgreSQL thiab hnub tim Math tivthaiv los ntawm MonetDB, nws tus kheej kev siv lub qhov rais ua haujlwm (raws li Segment Tree Aggregation algorithm), vectorized query execution engine (raws li Hyper-Pipelining Query Execution algorithm), lub tsev qiv ntawv-raws li cov lus qhia niaj hnub processor RE2, nws tus kheej cov lus nug optimizer thiab MVCC mechanism rau kev tswj hwm kev ua haujlwm ib txhij (Multi-Version Concurrency Control).
Qhov project code faib los ntawm nyob rau hauv MIT daim ntawv tso cai. Kev loj hlob tseem nyob rau theem tsim kev sim tso tawm.

Tau qhov twg los: opennet.ru