Bug 1800371 Comment 0 Edit History

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The current query is slower than a NOT EXISTS because it has to extract the id from 

old query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
18	0	0	LIST SUBQUERY 2
21	18	0	SCAN TABLE moz_icons_to_pages
47	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

new query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
15	0	0	CORRELATED SCALAR SUBQUERY 2
19	15	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)
36	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

The new query on my system takes 100ms VS 150ms of the old one
The current query is slower than a NOT EXISTS because it has to extract the id from 

old query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
18	0	0	LIST SUBQUERY 2
21	18	0	SCAN TABLE moz_icons_to_pages
47	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

new query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
15	0	0	CORRELATED SCALAR SUBQUERY 2
19	15	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)
36	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

The new query on my system takes 100ms VS 150ms of the old one (tested updating DB Browser for Sqlite to the latest sqlite3.dll from sqlite.org)
The current query is slower than a NOT EXISTS because it has to extract the id from moz_pages_w_icons

old query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
18	0	0	LIST SUBQUERY 2
21	18	0	SCAN TABLE moz_icons_to_pages
47	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

new query plan
3	0	0	SCAN TABLE moz_pages_w_icons
6	0	0	USING INDEX moz_places_url_hashindex FOR IN-OPERATOR
15	0	0	CORRELATED SCALAR SUBQUERY 2
19	15	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)
36	0	0	SEARCH TABLE moz_icons_to_pages USING PRIMARY KEY (page_id=?)

The new query on my system takes 100ms VS 150ms of the old one (tested updating DB Browser for Sqlite to the latest sqlite3.dll from sqlite.org)

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