\n\t1,\u67e5\u770b\u6267\u884c\u8ba1\u5212\u65b9\u5f0f\uff1a
\n\t1\uff09\u4ee5\u884c\u8868\u65b9\u5f0f\u8fd4\u56de\u6267\u884c\u8ba1\u5212\u4fe1\u606f\uff08\u6811\u72b6\u7ed3\u6784\uff0c\u81ea\u4e0a\u800c\u4e0b\uff0c\u81ea\u5de6\u800c\u53f3\u67e5\u770b\uff0c\u901a\u8fc7TotalSubtreeCost\u67e5\u770b\u5f00\u9500\uff09\uff0c\u4e0d\u6267\u884csql\u8bed\u53e5
\n\tset showplan_all on
\n\tgo
\n\tselect * from AWBuildVersion
\n\tset showplan_all off<\/p>\n
\n\t2\uff09XML\u65b9\u5f0f\u8fd4\u56de\u6267\u884c\u8ba1\u5212\u4fe1\u606f\uff0c\u4e0d\u6267\u884csql\u8bed\u53e5
\n\tset showplan_XML on
\n\tselect * from AWBuildVersion
\n\tset showplan_XML off<\/p>\n
\n\t3)\u4ee5\u884c\u8868\u65b9\u5f0f\u8fd4\u56de\u6267\u884c\u8ba1\u5212\u4fe1\u606f\uff0c\u6267\u884csql\u8bed\u53e5\uff0c\u56e0\u4e3a\u6267\u884c\u4e86sql\u8bed\u53e5\uff0c\u6545\u5728\u8fd4\u56de\u7684\u6267\u884c\u8ba1\u5212\u7ed3\u679c\u4e2d\u5305\u542b\u4e86\u6bcf\u4e00\u6b65\u6267\u884c\u540e\u8fd4\u56de\u7684\u884c\u6570\uff08\u8868\u5934\u7684rows\u5b57\u6bb5\uff09\uff0c\u53ef\u4e0e
\n\t\u9884\u4f30\u7684\u884c\u6570\u505a\u6bd4\u8f83\uff0c\u5206\u6790\u6267\u884c\u8ba1\u5212\u7684\u6548\u679c\u3002
\n\tset statistics profile on
\n\tselect * from AWBuildVersion
\n\tset statistics profile off
\n\t4)\u5bf9\u4e8e\u6267\u884c\u8ba1\u5212\uff0c\u5206\u6790\u5176\u662f\u5426\u6070\u5f53\uff0c\u9996\u5148\u8981\u770b\u9884\u4f30\u884c\u6570 estimaterows\u4e0erows\u662f\u5426\u76f8\u540c\uff0c\u82e5\u5dee\u522b\u8f83\u5927\uff0c\u5dee\u51e0\u5343\uff0c\u90a3\u4e48\u8bf4\u660e\u9884\u4f30\u51fa\u95ee\u9898\uff0c
\n\t\u539f\u56e0\u662f\u7edf\u8ba1\u4fe1\u606f\u4e0d\u5bf9\uff0c\u8fd9\u65f6\u53ef\u901a\u8fc7\u91cd\u5efa\u7d22\u5f15\u6765\u66f4\u65b0\u7edf\u8ba1\u4fe1\u606f\u3002\uff08\u91cd\u5efa\u7d22\u5f15\u7684\u597d\u5904\uff1a1\uff0c\u66f4\u65b0\u4e86\u7edf\u8ba1\u4fe1\u606f\uff0c\u6267\u884c\u8ba1\u5212\u9884\u4f30\u66f4\u52a0\u6b63\u786e\uff0c2\uff0c\u5904\u7406\u4e86\u6570\u636e\u788e\u7247\uff0c\u67e5\u627e\u901f\u5ea6\u63d0\u5347\u3002\uff09
\n\t\u7b2c\u4e8c\u5c31\u662f\u67e5\u770btotalsubtreecost\u5f00\u9500\u3002<\/p>\n
\n\t\u6267\u884c\u8ba1\u5212\u7ed3\u679c\u8868\u4fe1\u606f\uff1a
\n\tROWS:\u6267\u884c\u8ba1\u5212\u7684\u6bcf\u4e00\u6b65\u8fd4\u56de\u7684\u5b9e\u9645\u884c\u6570\u3002
\n\tExecutes:\u6267\u884c\u8ba1\u5212\u7684\u6bcf\u4e00\u6b65\u88ab\u8fd0\u884c\u4e86\u591a\u5c11\u6b21\uff1a\u82e5\u6b64\u503c\u5f88\u5927\uff0c\u53c8\u53d1\u751f\u5728nested loop\u4e2d\uff0c\u8981\u770b\u662f\u5426\u5e94\u91cd\u65b0\u7f16\u8bd1\uff0c\u4ee5\u4f7f\u7528Hash JOIN
\n\tStmtText:\u6267\u884c\u8ba1\u5212\u7684\u5177\u4f53\u5185\u5bb9\u3002
\n\tEstimateRows:\u9884\u4f30\u7684\u6bcf\u4e00\u6b65\u8fd4\u56de\u7684\u884c\u6570\u3002\u8981\u4e0eROWS\u505a\u6bd4\u5bf9\uff0c\u4ee5\u5206\u6790\u9884\u4f30\u662f\u5426\u6b63\u786e\u3002
\n\tEstimateIO:\u6bcf\u4e00\u6b65\u9884\u4f30\u7684IO\u5f00\u9500\u3002
\n\tEstimateCPU:\u6bcf\u4e00\u6b65\u9884\u4f30\u7684CPU\u5f00\u9500\u3002
\n\tTotalSubtreeCost:\u636eEstimateIO\u4e0eEstimateCPU\u901a\u8fc7\u67d0\u79cd\u8ba1\u7b97\u516c\u5f0f\uff0c\u8ba1\u7b97\u51fa\u6bcf\u4e00\u6b65\u6267\u884c\u8ba1\u5212\u5b50\u6811\u7684cost\uff0c\u5305\u542b\u81ea\u5df1\u7684cost\u548c\u5b83\u7684\u6240\u6709\u4e0b\u5c42\u6b65\u9aa4\u7684cost\u603b\u548c\u3002
\n\tWarnings:SqlServer\u6267\u884c\u6bcf\u4e00\u6b65\u65f6\u9047\u5230\u7684\u8b66\u544a\uff0c\u5982\u67d0\u4e00\u6b65\u6ca1\u6709\u7edf\u8ba1\u4fe1\u606f\u8fd0\u884c\u9884\u4f30\u7b49\u3002
\n\tParallel:\u662f\u5426\u4f7f\u7528\u4e86\u5e76\u884c\u7684\u6267\u884c\u8ba1\u5212\u3002<\/p>\n
\n\t
\n\t2\uff0cJOIN\u8fde\u63a5\u79cd\u7c7b
\n\t1\uff09Nested Loops JOIN:\u5bf9\u4e8eA\u8868\u4e2d\u6ee1\u8db3\u6761\u4ef6\u7684\u6bcf\u4e00\u884c\uff0c\u904d\u5386B\u8868,\u5728\u6267\u884c\u8ba1\u5212\u4fe1\u606f\u4e2d\uff0c\u4ee5Nested\u5305\u62ec\uff0c\u5171\u6709\u4e24\u884c\uff0c\u6bcf\u884c\u6267\u884c\u8fc7\u6ee4\u540e\uff0c\u4ee5Nested\u8fdb\u884c\u8fde\u63a5\u3002
\n\t \u9009\u8fc7\u6ee4\u540e\u8fde\u63a5\u3002
\n\t\u5f3a\u5236\u7528: inner loop\/merge\/hash join
\n\t\u4f18\u70b9\uff1a\u4e0d\u9700\u8981SQLSERVER\u4e3aJOIN\u5efa\u7acb\u989d\u5916\u7684\u6570\u636e\u7ed3\u6784\uff0c\u4e5f\u4e0d\u7528\u5360\u7528tempdb\u7a7a\u95f4\u3002
\n\t\u4e0d\u8db3\uff1a\u590d\u6742\u5ea6\u662f\u4e24\u8868\u884c\u6570\u76f8\u4e58\uff0c\u9002\u7528\u4e8e\u4e24\u8868\u6570\u636e\u96c6\u6bd4\u8f83\u5c0f\u7684\u60c5\u51b5\u4e0b\u3002B\u8868\u6700\u597d\u6709\u7d22\u5f15\u3002
\n\t2)Merge Join\uff1a\u4eceA\u8868\u4e2d\u53d6\u4e00\u6761\u8bb0\u5f55\uff0cB\u8868\u4e2d\u4e5f\u53d6\u4e00\u6761\uff0c\u6bd4\u8f83\u662f\u5426\u76f8\u7b49\uff0c\u82e5\u76f8\u7b49\uff0c\u5219\u4e24\u884c\u8fde\u63a5\u8d77\u6765\u8fd4\u56de\uff0c\u82e5\u4e0d\u7b49\uff0c\u5219\u820d\u6389\u5c0f\u7684\u90a3\u4e2a\u503c\uff0c
\n\t\u63a5\u987a\u5e8f\u53d6\u4e0b\u4e00\u4e2a\u8f83\u5927\u7684\u503c\u8fdb\u884c\u6bd4\u8f83\uff0c\u76f4\u5230A\u4e0eB\u8868\u5176\u4e2d\u4e4b\u4e00\u904d\u5386\u5b8c\u3002
\n\t\u7531\u6b64\u5b9a\u4e49\u53ef\u4ee5\uff1a1\uff0cMerge Join\u8981\u6c42\u4e24\u8868\u662f\u6392\u5e8f\u8fc7\u7684\uff0c\u82e5\u6ca1\u6709\u6392\u5e8f\uff0c\u5219\u4f1a\u6267\u884c\u5148\u6392\u5e8f\uff0c\u6545\u9644\u52a0\u4f5c\u7528\u662f\u8fd4\u56de\u7684\u7ed3\u679c\u90fd\u662f\u6709\u5e8f\u7684\u3002
\n\t 2\uff0c\u53ea\u80fd\u8fdb\u884c\u503c\u76f8\u7b49\u7684\u8fd0\u7b97,ON\u6761\u4ef6\u540e\u4e3a=\u3002
\n\t 3\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u662f\u6bcf\u8868\u7b26\u5408\u6761\u4ef6\u7684\u884c\u6570\uff0c\u5b83\u9002\u7528\u4e8e\u5927\u6570\u636e\u91cf\u7684\u60c5\u51b5\u3002
\n\t 4\uff0c\u4e3a\u9632\u6b62\u6570\u636e\u6709\u91cd\u590d\u800c\u88ab\u8fc7\u6389\u7684\u7ed3\u679c\uff0c\u4f1a\u5bf9B\u8868\u5df2\u904d\u5386\u8fc7\u7684\u653e\u5230tempdb\u4e2d\uff0c\u4ee5\u5907\u67e5\u8be2\uff0c\u79f0\u4e4b\u4e3amany-to-many
\n\t \u6545\u7531\u4e0a\u77e5\uff0c\u5b83\u7684\u590d\u6742\u5ea6\u4f4e\uff0c\u82e5\u8868\u4e2d\u65e0\u7d22\u5f15\uff0c\u8981\u6392\u5e8f\u3002\u5b83\u8fd8\u9700\u8981\u989d\u5916\u7684many-to-many\uff0c\u4e0d\u8fc7\u82e5\u8868\u5b57\u6bb5\u9650\u5b9aunique\uff0c\u5219\u76f8\u5f53\u4e8e\u544a\u8bc9sqlserver
\n\t\u8fd9\u662f\u552f\u4e00\u7684\uff0c\u4e0d\u4f1a\u91cd\u590d\uff0c\u90a3\u4e48\u4e5f\u5c31\u4e0d\u4f1a\u7528many-to-many\u4e86\u3002
\n\t3\uff09Hash Join:\u4ee5\u54c8\u5e0c\u7b97\u6cd5\u4e3a\u4e3b\u7684\u8fde\u63a5\u65b9\u6cd5\uff0c\u5206\u4e3a\u4e24\u6b65\uff0c\u7b2c\u4e00\u6b65\uff0c\u5728\u5185\u5b58\u6216tempdb\u4e2d\u5bf9B\u8868\u5efa\u7acbhash\u8868\uff0c\u7b2c\u4e8c\u6b65\uff0c\u5c06\u53e6\u4e00\u8868\u503c\u4ee3\u5165\u67e5\u627e\u3002\u9002\u7528\u4e8e
\n\t\u5927\u6570\u636e\u91cf\u7684\u60c5\u51b5\uff0c\u7279\u522b\u662f\u65e0\u7d22\u5f15\u8fd9\u79cd\u7684\u65e0\u5e8f\u6570\u636e\u3002\u5b83\u5efa\u7acbhash\u8868\uff0c\u6545\u8981\u6c6a\u6d88\u8017\u5185\u5b58\uff0c\u8981\u8fdb\u884chash\u5339\u914d\uff0c\u8981\u6d88\u8017CPU.<\/p>\n
\n\t\u5bf9\u7167\u8868\u5982\u4e0b\uff1a
\n\t Nested Loop Joion Merge Join Hash Join
\n\t\u9002\u7528\u573a\u666f \u5c0f\u6570\u636e\u91cf \u6570\u636e\u91cf\u4e2d\u7b49 \u6570\u636e\u91cf\u5927
\n\tON\u662f\u5426\u8981\u6c42\u76f8\u7b49 \u4e0d\u9700\u8981 \u9700\u8981 \u9700\u8981
\n\t\u662f\u5426\u4f7f\u7528\u5185\u5b58 \u4e0d\u9700\u8981 \u4e0d\u4f7f\u7528 \u9700\u8981\u4f7f\u7528\u5185\u5b58\u5efa\u7acbhash\u8868\u3002
\n\t\u662f\u5426\u4f7f\u7528tempdb \u4e0d\u9700\u8981 many-to-many\u7528 \u4f7f\u7528\u5efa\u7acbhash\u8868<\/p>\n
\n\t3, \u5176\u5b83\u8fd0\u7b97\u7b26
\n\t1\uff09\u6d41\u8fd0\u7b97\uff1aStream Aggregation\uff08\u5c06\u6570\u636e\u96c6\u6392\u6210\u4e00\u4e2a\u961f\u5217\u4ee5\u540e\u505a\u8fd0\u7b97\uff09,\u5982\u6267\u884c\u805a\u5408\u51fd\u6570\u3001Group By\u65f6\uff0c\u4f1a\u51fa\u73b0\u6d41\u805a\u5408\u3002
\n\t2) \u54c8\u5e0c\u5339\u914d\uff1aHash Aggregation\uff08\u7c7b\u4f3c\u4e8eHash Join\uff0c\u9700\u8981SQL Server\u5148\u5efa\u7acbHash\u8868\uff0c\u7136\u540e\u624d\u80fd\u505a\u8fd0\u7b97\uff09\u5982\u6267\u884c\u805a\u5408\u51fd\u6570\u65f6\uff0c\u6570\u636e\u91cf\u5927\u65f6\uff0c\u4f1a\u51fa\u73b0\u54c8\u5e0c\u5339\u914d\u3002
\n\t3)\u8fde\u63a5\uff1aConcatenationunion all\u4e0eunion:\u4f1a\u6709\u4e00\u4e2a\u8fde\u63a5\u64cd\u4f5c\uff0c\u540d\u4e3aConcatenation,\u5c06\u6570\u636e\u96c6\u8fde\u63a5\u8d77\u6765\uff0c\u4e0d\u8fc7\uff0cunion\u5728Concatenation\u4e4b\u540e\uff0c\u4f1a\u518d\u505a\u4e00\u6b65\u6392\u5e8f\uff08\u4ee5\u4fbf\u6613\u4e8e\u5206\u7ec4\uff09\u4e0e\u5206\u7ec4\uff0c\u4ee5\u53d6\u51fa\u552f\u4e00\uff0c\u6bd4\u8f83\u6d88\u8017\u8d44\u6e90\u3002
\n\t4\uff09\u5e76\u884c\u8ba1\u7b97\uff1aParallelism:\u5f53sqlserver\u53d1\u73b0\u67d0\u4e2a\u8981\u5904\u7406\u7684\u6570\u636e\u96c6\u6bd4\u8f83\u5927\uff0ccost\u6bd4\u8f83\u9ad8\u65f6\uff0c\u82e5\u670d\u52a1\u5668\u6709\u591a\u4e2acpu\uff0csqlserver\u5c31\u4f1a\u5c1d\u8bd5\u4f7f\u7528
\n\t\u5e76\u884c\u7684\u65b9\u6cd5\uff0c\u5c06\u4e00\u4e2a\u6570\u636e\u96c6\u5206\u6210\u82e5\u5e72\u4e2a\uff0c\u7531\u82e5\u5e72\u4e2a\u7ebf\u7a0b\u540c\u65f6\u5904\u7406.<\/p>\n
\n\t—————————————-\u53c2\u6570\u5316\u95ee\u9898———————————————————
\n\t\u53c2\u6570\u95ee\u9898
\n\t\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\u65f6\uff0c\u6267\u884c\u8ba1\u5212\u4f1a\u91cd\u7528\uff0c\u4f46\u56e0\u6570\u636e\u7684\u4e0d\u540c\uff0c\u4f20\u5165\u4e0d\u540c\u7684\u6570\u636e\uff0c\u53ef\u80fd\u4f1a\u9020\u6210\u73b0\u6709\u6267\u884c\u8ba1\u5212\u4e0d\u7b26\u5408\u5b9e\u9645\uff0c\u9020\u6210\u6548\u679c\u6162\uff0c\u6b64\u65f6\u7528
\n\tsql\u6784\u9020\u53cd\u800c\u5feb\u7684\u7ed3\u679c\u51fa\u73b0\u3002
\n\t1\uff0c\u5b58\u50a8\u8fc7\u7a0b\u7684\u53c2\u6570\u5206\u4e3a\u4e24\u7c7b\uff1a1\uff0c\u662f\u4f20\u5165\u53c2\u6570\uff0c2\u662f\u5185\u90e8\u53c2\u6570
\n\t1\uff0c\u4f20\u5165\u53c2\u6570\uff0c\u82e5\u6267\u884c\u8fc7\u7a0b\u7684\u6267\u884c\u8ba1\u5212\u4e0e\u62ff\u51fa\u6765\u6267\u884c\u5f97\u5230\u7684\u6267\u884c\u8ba1\u5212\u4e0d\u540c\uff0c\u53ef\u80fd\u5c31\u53d1\u751f\u4e86\u53c2\u6570\u5316\u95ee\u9898\uff0c\u6bd4\u5982\u7b2c\u4e00\u6b21\u6267\u884c\u65f6\u662fnested loop\uff0c
\n\t\u6267\u884c\u8ba1\u5212\u7f13\u5b58\u8d77\u6765\uff0c\u4e0b\u6b21\u67e5\u8be2\u7684\u6570\u636e\u8303\u56f4\u5f88\u5927\uff0c\u5e94\u7528hash join\u7684\uff0c\u4f46\u56e0\u91cd\u7528\u4e86\u6267\u884c\u8ba1\u5212\uff0c\u4ecd\u7528nested loop \u6267\u884c\u3002\u7531\u6b64\u77e5\uff0c\u53c2\u6570\u95ee\u9898\u53ea\u4f1a
\n\t\u53d1\u751f\u5728\u4e00\u4e9b\u8868\u683c\u91cc\u7684\u6570\u636e\u5206\u5e03\u4e0d\u5747\u5300\uff0c\u6216\u8005\u7528\u6237\u4f20\u5165\u7684\u53c2\u6570\u5f88\u4e0d\u5747\u5300\u7684\u60c5\u51b5\u4e0b\uff0c\u5982\uff1a\u5927\u90e8\u5206\u5ba2\u6237\u67e5\u8be2\u7684\u662f\u4e00\u5929\u7684\u6570\u636e\uff0c\u4f46\u6709\u4e00\u4e2a\u67e5\u4e00\u5e74\u7684
\n\t\u6570\u636e\u5c31\u4f1a\u51fa\u73b0\u95ee\u9898\uff0c\u5e38\u89c1\u7684\u662f\u8be5\u7528hash join\u7684\u7528\u4e86nested join.
\n\t\u89e3\u51b3\u4e4b\u9053\uff1a1\uff09\u52a8\u6001sql\u6267\u884c\u3002
\n\t2\uff09\u5f3a\u5236\u91cd\u65b0\u7f16\u8bd1\uff1a
\n\t\uff081\uff09\u5b58\u50a8\u8fc7\u7a0b\u7ea7\uff1awith recompile :\u5728\u521b\u5efa\u5b58\u50a8\u8fc7\u7a0b\u65f6\u52a0\u5165\uff0c\u90a3\u4e48\u6574\u4e2a\u5b58\u50a8\u8fc7\u7a0b\u4f1a\u5b9e\u65f6\u7f16\u8bd1\uff0c\u6548\u7387\u4f4e\u4e00\u4e9b\u3002
\n\t\uff082\uff09\u8bed\u53e5\u7ea7\uff1aoption(recompile)\uff1a\u5728\u8bed\u53e5\u540e\u52a0\u5165\uff0c\u6bd4\u8f83\u7cbe\u7ec6\uff0c\u53ea\u6709\u52a0\u4e86\u8fd9\u4e2a\u8bed\u53e5\u7684sql\u624d\u4f1a\u91cd\u65b0\u7f16\u8bd1\u6267\u884c\u8ba1\u5212\uff0c\u6574\u4e2a\u5b58\u50a8\u8fc7\u7a0b\u4e0d\u4f1a\u91cd\u65b0\u7f16\u8bd1\uff0c\u6545\u6548\u7387\u4f1a\u9ad8\u4e00\u4e9b\uff0c
\n\t\u5e76\u4e14\u5982\u679c\u6709if else,\u5e76\u7528\u6ca1\u6709\u7ecf\u8fc7\u6b64\u8bed\u53e5\uff0c\u4e5f\u4e0d\u4f1a\u91cd\u65b0\u7f16\u8bd1\u3002<\/p>\n
\n\t2\uff0c\u5bf9\u5165\u5185\u90e8\u53c2\u6570\uff0c\u662f\u5728\u6267\u884c\u8fc7\u7a0b\u65f6\u624d\u80fd\u5f97\u5230\u7684\uff0c\u5728\u7f16\u8bd1\u65f6\u5e76\u4e0d\u77e5\u9053\u5b83\u7684\u5927\u5c0f\uff0c\u4f1a\u6839\u636e\u8868\u683c\u6570\u636e\u91cf\u9884\u4f30\u4e00\u4e2a\u4e2d\u95f4\u503c\uff0c\u6027\u80fd\u4e0d\u662f\u6700\u597d\u4e5f\u4e0d\u662f\u6700\u574f\u3002For example, consider a column X, containing 10 rows
\n\twith values 1, 2, 3, 3, 3, 3, 3, 4, 5, 5. The optimizer would always estimate that a "WHERE
\n\tX=value" query will return 2 rows (total number of rows divided by number of distinct
\n\tvalues)<\/p>\n
\n\t—————————————\u603b\u7ed3—————————————————————————–
\n\t\u67e5\u770b\u6267\u884c\u8ba1\u5212
\n\tSET statistics profile on
\n\t1\uff09\u6bd4\u8f83rows\u4e0eestimaterows\u662f\u5426\u5dee\u522b\u8f83\u5927\uff0c
\n\t\u82e5\u8f83\u5927\uff0c\u539f\u56e0\u662f1\uff09\u7edf\u8ba1\u4fe1\u606f\u4e0d\u5bf9\uff0c\u8fd9\u65f6\u53ef\u901a\u8fc7\u91cd\u5efa\u7d22\u5f15\u6765\u66f4\u65b0\u7edf\u8ba1\u4fe1\u606f\u3002\uff08\u91cd\u5efa\u7d22\u5f15\u7684\u597d\u5904\uff1a1\uff0c\u66f4\u65b0\u4e86\u7edf\u8ba1\u4fe1\u606f\uff0c\u6267\u884c\u8ba1\u5212\u9884\u4f30\u66f4\u52a0\u6b63\u786e\uff0c2\uff0c\u5904\u7406\u4e86\u6570\u636e\u788e\u7247\uff0c\u67e5\u627e\u901f\u5ea6\u63d0\u5347\u3002\uff09
\n\t2\uff09Executes\u82e5Executes\u503c\u5f88\u5927\uff0c\u53c8\u53d1\u751f\u5728nested loop\u4e2d\uff0c\u4e0d\u9002\u5408\u81ea\u5df1\u7684\u6267\u884c\u8ba1\u5212\uff0c\u591a\u53d1\u751f\u5728\u5b58\u50a8\u8fc7\u7a0b\u4e2d\uff0c\u6b64\u65f6\u8981\u5f3a\u5236\u91cd\u65b0\u7f16\u8bd1 option(recompile)
\n\t3\uff09\u67e5\u770btotalsubtreecost\u5f00\u9500\uff0c\u8be5\u5efa\u7d22\u5f15\u5efa\u7d22\u5f15\u3002
\n\t4\uff09\u82e5\u662f\u626b\u63cf\u800c\u4e0d\u662f\u67e5\u627e\uff0c\u539f\u56e0\u662flookup\u67e5\u627e\u4e3b\u952e\u5f00\u9500\u5f88\u5927\uff0c\u4e0d\u5982\u76f4\u63a5\u626b\u63cf\u6765\u5f97\u5feb\uff0c\u6b64\u79cd\u60c5\u51b5\u4e0b\u770b\u80fd\u5426\u6d88\u9664select\u4e2d\u7684\u5b57\u6bb5\u6570\uff0c\u907f\u514dlookup\u3002
\n\t5)\u6e05\u7a7a\u7f13\u5b58\uff1adbcc freeproccache<\/p>\n","protected":false},"excerpt":{"rendered":"
1,\u67e5\u770b\u6267\u884c\u8ba1\u5212\u65b9\u5f0f\uff1a 1\uff09\u4ee5\u884c\u8868\u65b9\u5f0f\u8fd4\u56de\u6267\u884c\u8ba1\u5212\u4fe1\u606f\uff08\u6811\u72b6\u7ed3\u6784\uff0c\u81ea\u4e0a\u800c\u4e0b\uff0c\u81ea\u5de6\u800c\u53f3\u67e5\u770b\uff0c\u901a\u8fc7TotalSub […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-2124","post","type-post","status-publish","format-standard","hentry","category-sql-server"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts\/2124","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/comments?post=2124"}],"version-history":[{"count":0,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/posts\/2124\/revisions"}],"wp:attachment":[{"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/media?parent=2124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/categories?post=2124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/enjoyasp.net\/index.php\/wp-json\/wp\/v2\/tags?post=2124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}