我安装了Postgis的Postgres 9.5数据库。我创建了一个由大约200个表组成的物化视图。整个视图包含3,447,885条记录。每条记录都有一个几何类型的位置字段。当我在边界框中查询位置为ST_With的所有记录时，返回126,630行需要15.1秒。
我在字段上构建了一个GIST索引并运行查询，它仍然需要15.1才能返回126,630行。
示例查询：
SELECT ST_AsText (location)
FROM myview
WHERE ST_Within (location, ST_Geometry (....
我是否应该看到该大小的物化视图的显着性能提升？有什么我可以找到来表明性能问题的根源吗？
创建索引：
create index myview_location_gist on myview using gist (location);
解释分析：
'Bitmap Heap Scan on myview (cost=130.56..11653.11 rows=1149 width=40) (actual time=18.377..564.760 rows=126330 loops=1)'
' Recheck Cond: ('0103000020110F00000100000005000000D151D81DE90461C1831E458318835241D151D81DE90461C1D7A37045F81B53415C8FC23C79B860C1D7A37045F81B53415C8FC23C79B860C1831E458318835241D151D81DE90461C1831E458318835241'::geometry ~ location)'
' Filter: _st_contains('0103000020110F00000100000005000000D151D81DE90461C1831E458318835241D151D81DE90461C1D7A37045F81B53415C8FC23C79B860C1D7A37045F81B53415C8FC23C79B860C1831E458318835241D151D81DE90461C1831E458318835241'::geometry, location)'
' Rows Removed by Filter: 3'
' Heap Blocks: exact=17361'
' -> Bitmap Index Scan on myview_location_gist (cost=0.00..130.28 rows=3448 width=0) (actual time=15.923..15.923 rows=126333 loops=1)'
' Index Cond: ('0103000020110F00000100000005000000D151D81DE90461C1831E458318835241D151D81DE90461C1D7A37045F81B53415C8FC23C79B860C1D7A37045F81B53415C8FC23C79B860C1831E458318835241D151D81DE90461C1831E458318835241'::geometry ~ location)'
'Planning time: 0.080 ms'
'Execution time: 570.068 ms'