syntaxsql复制 <query_hint>::={ {HASH|ORDER}GROUP| {CONCAT|HASH|MERGE}UNION| {LOOP|MERGE|HASH}JOIN|DISABLE_OPTIMIZED_PLAN_FORCING|EXPANDVIEWS|FAST<integer_value>|FORCEORDER| {FORCE|DISABLE}EXTERNALPUSHDOWN| {FORCE
经过词法语法分析器生成AST（Abstract Syntax Tree），会被优化器处理生成生成执行计划，再由执行引擎执行，下图以MySQL架构为例展示词法语法分析器所处的位置。本文通过介绍词法语法分析器技术和业界的做法，以及过去使用自动生成的词法语法分析器遇到的问题，分享自研SQL Parser的设计与实践，以及其带来的性能和功能的提升。
Transact-SQL syntax conventions Syntax syntaxsql WITH([ [ , ] ...n ] )::={NOEXPAND|INDEX(<index_value>[ , ...n ] ) |INDEX= (<index_value>) |FORCESEEK[ (<index_value>(<index_column_name>[ , ... ] ) ) ] |FORCESCAN|HOLDLOCK|NOLOCK|NOWAIT|PAGLOCK|READCOMMITTED|READCOMMITTEDLOC...
syntaxsql <query_hint>::={ {HASH|ORDER}GROUP| {CONCAT|HASH|MERGE}UNION| {LOOP|MERGE|HASH}JOIN|DISABLE_OPTIMIZED_PLAN_FORCING|EXPANDVIEWS|FAST<integer_value>|FORCEORDER| {FORCE|DISABLE}EXTERNALPUSHDOWN| {FORCE|DISABLE}SCALEOUTEXECUTION|IGNORE_NONCLUSTERED_COLUMNSTORE_INDEX|KEEPPLAN|KEEPFIXEDPLAN|MAX...
syntaxsql Copy <query_hint> ::= { { HASH | ORDER } GROUP | { CONCAT | HASH | MERGE } UNION | { LOOP | MERGE | HASH } JOIN | DISABLE_OPTIMIZED_PLAN_FORCING | EXPAND VIEWS | FAST <integer_value> | FORCE ORDER ...
syntaxsql 複製 <query_hint> ::= { { HASH | ORDER } GROUP | { CONCAT | HASH | MERGE } UNION | { LOOP | MERGE | HASH } JOIN | DISABLE_OPTIMIZED_PLAN_FORCING | EXPAND VIEWS | FAST <integer_value> | FORCE ORDER | { FORCE | DISABLE } EXTERNALPUSHDOWN | { FORCE | DISABLE } ...
syntaxsql 複製 <join_hint> ::= { LOOP | HASH | MERGE | REMOTE | REDUCE | REPLICATE | REDISTRIBUTE [(columns count)]} 引數 { LOOP |HASH |MERGE } 適用於: Azure SQL Database、Azure SQL 受控實例、SQL 分析端點、Microsoft網狀架構中的 SQL 資料庫、Microsoft網狀架構倉儲 指定查詢中的聯結應...
syntaxsql复制 WITH([ [ , ] ...n ] )::={NOEXPAND|INDEX(<index_value>[ , ...n ] ) |INDEX= (<index_value>) |FORCESEEK[ (<index_value>(<index_column_name>[ , ... ] ) ) ] |FORCESCAN|HOLDLOCK|NOLOCK|NOWAIT|PAGLOCK|READCOMMITTED|READCOMMITTEDLOCK|READPAST|READUNCOMMITTED|REPEATABL...
syntaxsql复制 WITH([ [ , ] ...n ] )::={NOEXPAND|INDEX(<index_value>[ , ...n ] ) |INDEX= (<index_value>) |FORCESEEK[ (<index_value>(<index_column_name>[ , ... ] ) ) ] |FORCESCAN|HOLDLOCK|NOLOCK|NOWAIT|PAGLOCK|READCOMMITTED|READCOMMITTEDLOCK|READPAST|READUNCOMMITTED|REPEATABL...
经过词法语法分析器生成AST(Abstract Syntax Tree),会被优化器处理生成生成执行计划,再由执行引擎执行,下图以MySQL架构为例展示词法语法分析器所处的位置。 本文通过介绍词法语法分析器技术和业界的做法,以及过去使用自动生成的词法语法分析器遇到的问题,分享自研SQL Parser的设计与实践,以及其带来的性能和功能的提升。