如何提升效率低下的sql查询速度？

[[{"txt": "sql\u67e5\u8be2\u4f18\u5316\u8bb2\u89e3"}, {"img": ["https://exp-picture.cdn.bcebos.com/51cd85cec7f88a7772f065f86e4a2f27e6eff881.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}], [{"txt": ["\u5de5\u5177/\u539f\u6599"]}, {"txt": "MySQL8.0.12"}, {"txt": "Navicat"}], [{"txt": ["\u65b9\u6cd5/\u6b65\u9aa4"]}, {"txt": "\u67e5\u770b\u539f\u59cb\u5458\u5de5\u8868, \u8bb0\u5f55\u5c06\u6309\u987a\u5e8f\u5b58\u50a8\u5728\u78c1\u76d8\u4e0a, \u5f88\u53ef\u80fd\u662f\u6309\u5458\u5de5\u53f7\u5217\u7684\u987a\u5e8f\u5b58\u50a8, \u56e0\u6b64\u5458\u5de5\u7f16\u53f7101\u5c06\u9075\u5faa 100, \u4f9d\u6b64\u7c7b\u63a8\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/025d87c0affce1861a0245c61f1fbee435daeb81.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b, \u4ee5\u8fd9\u79cd\u65b9\u5f0f\u5b58\u50a8\u6570\u636e\u6ca1\u6709\u591a\u5927\u610f\u4e49;\u5f88\u5c11\u6709\u60c5\u51b5\u4e0b, \u4f60\u4f1a\u5e0c\u671b\u6309\u5458\u5de5\u7f16\u53f7\u7684\u987a\u5e8f\u5217\u51fa\u5458\u5de5\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/a68c126efbf202b33bfa74cf30f4da5873dadb81.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u5bf9\u6b64\u6570\u636e\u7684\u4e00\u4e2a\u53ef\u80fd\u7684\u67e5\u8be2\u662f\u67e5\u627e\u5728\u7279\u5b9a\u529e\u516c\u5ba4\u5de5\u4f5c\u7684\u6240\u6709\u5458\u5de5:SELECT * FROM employees WHERE office_location_id=2;"}, {"img": ["https://exp-picture.cdn.bcebos.com/5917cb3da824d8e993ff56d2da598540112ac881.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u6b64\u67e5\u8be2\u5c06\u9700\u8981\u6309\u987a\u5e8f\u68c0\u67e5\u6bcf\u4e00\u884c, \u4ee5\u67e5\u770b WHERE \u8c13\u8bcd\u662f\u5426\u5339\u914d\u3002\u5982\u679c\u8868\u6709\u51e0\u5343\u884c, \u5219\u6b64\u67e5\u8be2\u53ef\u80fd\u9700\u8981\u4e00\u6bb5\u65f6\u95f4, \u5c24\u5176\u662f\u5728\u6ca1\u6709\u884c\u6ee1\u8db3\u6761\u4ef6\u7684\u60c5\u51b5\u4e0b\u3002"}, {"txt": "\u901a\u8fc7\u4e3a\u8be5\u5217\u6dfb\u52a0\u7d22\u5f15, \u6570\u636e\u5e93\u5c06\u63d0\u4f9b\u8be5\u5217\u7684\u76f4\u63a5\u67e5\u627e;\u7ed9\u51fa\u4e86\u884c\u4f4d\u7f6e\u7684\u76f4\u63a5\u5f15\u7528\u3002\u4e0b\u56fe\u8bf4\u660e\u4e86\u5b83\u7684\u5de5\u4f5c\u539f\u7406\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/35fa07efa25f0c14ad563f360d89a146b6b13886.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "office _ location _ id \u7684\u5206\u7ec4\u5c06\u5b58\u50a8\u5728\u6b64\u8868\u4e2d, \u6570\u636e\u5e93\u5c06\u4f7f\u7528\u5b83\u6765\u67e5\u627e\u57fa\u4e8e\u529e\u516c\u4f4d\u7f6e\u7684\u884c\u3002\u9700\u8981\u6743\u8861\u7684\u662f, \u5b58\u50a8\u7d22\u5f15\u9700\u8981\u66f4\u591a\u7684\u78c1\u76d8\u7a7a\u95f4\u3002\u4e0b\u56fe\u663e\u793a\u4e86\u5982\u4f55\u521b\u5efa\u6b64\u7d22\u5f15\uff1aCREATE INDEX office_loc_idx on employees (office_location_id);"}, {"img": ["https://exp-picture.cdn.bcebos.com/32fbcd41037de137b45bcf08f6c5cf672a5f2a86.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}, {"txt": "\u4e00\u65e6\u5230\u4f4d, \u63d2\u5165\u5230\u5458\u5de5\u8868\u4e2d\u4e5f\u4f1a\u5bfc\u81f4\u7d22\u5f15\u4e2d\u7684\u6761\u76ee, \u53ef\u80fd\u4f1a\u4f7f\u63d2\u5165\u65f6\u95f4\u66f4\u957f\u3002\u6743\u8861\u7684\u662f, \u67e5\u627e\u901f\u5ea6\u4f1a\u5feb\u5f97\u591a, \u7279\u522b\u662f\u5728\u8868\u683c\u5927\u5c0f\u589e\u957f\u5230\u51e0\u5343\u884c\u4e4b\u540e\u3002"}, {"img": ["https://exp-picture.cdn.bcebos.com/32fe25ef354f50b83b13456fdc4afa32929c1886.m2m?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_500%2Climit_1"]}]]