我们已经在amazonrds上将mysql 5.7数据库的副本迁移到mysql 8.0.11。在可能的情况下，一切都是一样的。已修改包含几何图形数据的表，因此几何图形列仅限于srid 0，并重建空间索引。两个数据库上的执行计划是相同的，表明查询使用的是空间索引。
在MySQL5.7上，以下查询需要0.001s在MySQL8上需要108s。查看mysql 8上“发送数据”的执行统计占100%。为什么？

SELECT r.roadid                             
FROM geocoder.osm_road r
WHERE mbrintersects(ST_Buffer(ST_GEOMETRYFROMTEXT('Point(-1.91289 52.58260)',0),0.0005), r.geometry)

我们有许多不同的空间查询，它们都是这样运行的，但特别是MBR相交和stïU相交看起来非常慢。更改为st_contains（如果可能）会有显著的改进（即上面的操作需要3秒而不是108秒），但这不适合许多查询，并且仍然比5.7中的慢很多。

Show Create Table for 5.7

CREATE TABLE `osm_road` (
  `roadid` bigint(20) NOT NULL,
  `reference` varchar(20) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL,
  `dictionary` longtext,
  `road_speed_limit` tinyint(4) unsigned NOT NULL,
  `road_speed_unitid` tinyint(1) NOT NULL,
  `road_type` tinyint(4) NOT NULL,
  `is_toll_road` bit(1) NOT NULL DEFAULT b'0',
  `is_one_way` bit(1) NOT NULL DEFAULT b'0',
  `countryid` smallint(6) DEFAULT NULL,
  `geometry` geometry NOT NULL,
  `datemodified` datetime DEFAULT CURRENT_TIMESTAMP,
  `datecreated` datetime DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`roadid`),
  UNIQUE KEY `id_roadid` (`roadid`),
  SPATIAL KEY `ix_road_geometry` (`geometry`),
  KEY `ix_road_reference` (`reference`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AVG_ROW_LENGTH=207

Show Create Table for 8.0.11

CREATE TABLE `osm_road` (
  `roadid` bigint(20) NOT NULL,
  `reference` varchar(20) DEFAULT NULL,
  `name` varchar(100) DEFAULT NULL,
  `dictionary` longtext,
  `road_speed_limit` tinyint(4) unsigned NOT NULL,
  `road_speed_unitid` tinyint(1) NOT NULL,
  `road_type` tinyint(4) NOT NULL,
  `is_toll_road` bit(1) NOT NULL DEFAULT b'0',
  `is_one_way` bit(1) NOT NULL DEFAULT b'0',
  `countryid` smallint(6) DEFAULT NULL,
  `geometry` geometry NOT NULL /*!80003 SRID 0 */,
  `datemodified` datetime DEFAULT CURRENT_TIMESTAMP,
  `datecreated` datetime DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`roadid`),
  UNIQUE KEY `id_roadid` (`roadid`),
  KEY `ix_road_reference` (`reference`),
  SPATIAL KEY `ix_road_geometry` (`geometry`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AVG_ROW_LENGTH=207

显示osmèu路的索引（5.7）

Table,Non_unique,Key_name,Seq_in_index,Column_name,Collation,Cardinality,Sub_part,Packed,Null,Index_type,Comment,Index_comment
osm_road,0,PRIMARY,1,roadid,A,18973144,NULL,NULL,,BTREE,,
osm_road,1,ix_road_geometry,1,geometry,A,18973154,32,NULL,,SPATIAL,,
osm_road,1,ix_road_reference,1,reference,A,199900,NULL,NULL,YES,BTREE,,

显示osmèu路索引（8.0.11）

Table,Non_unique,Key_name,Seq_in_index,Column_name,Collation,Cardinality,Sub_part,Packed,Null,Index_type,Comment,Index_comment,Visible
osm_road,0,PRIMARY,1,roadid,A,16194921,NULL,NULL,,BTREE,,,YES
osm_road,1,ix_road_reference,1,reference,A,86215,NULL,NULL,YES,BTREE,,,YES
osm_road,1,ix_road_geometry,1,geometry,A,16194921,32,NULL,,SPATIAL,,,YES

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--新增2019-01-27