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Overview
| Comment: | Link the optoverview.html document to the new expridx.html document. |
|---|---|
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
47d33de042d07cfb8462113461708b2b |
| User & Date: | drh 2015-10-07 19:40:17 |
Context
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2015-10-07
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| 22:42 | Fix a couple typos in the new docs. check-in: 255ed0fac7 user: mistachkin tags: trunk | |
| 19:40 | Link the optoverview.html document to the new expridx.html document. check-in: 47d33de042 user: drh tags: trunk | |
| 19:35 | Add a new documentation page that talks specifically about indexes on expressions. check-in: 8b6ed636e3 user: drh tags: trunk | |
Changes
Changes to pages/optoverview.in.
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that constraints column c, then terms that constrain columns a and b can
be used with the index but not terms that constraint columns d through z.
^Similarly, index columns will not normally be used (for indexing purposes)
if they are to the right of a
column that is constrained only by inequalities.
(See the [skip-scan optimization] below for the exception.)
}
HEADING 2 {Index term usage examples} idxexamp
PARAGRAPH {
^(For the index above and WHERE clause like this:
}
CODE {
... WHERE a=5 AND b IN (1,2,3) AND c IS NULL AND d='hello'
|
> > > > > > |
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that constraints column c, then terms that constrain columns a and b can be used with the index but not terms that constraint columns d through z. ^Similarly, index columns will not normally be used (for indexing purposes) if they are to the right of a column that is constrained only by inequalities. (See the [skip-scan optimization] below for the exception.) } PARAGRAPH { In the case of [indexes on expressions], whenever the word "column" is used in the foregoing text, one can substitute "indexed expression" (meaning a copy of the expression that appears in the [CREATE INDEX] statement) and everything will work the same. } HEADING 2 {Index term usage examples} idxexamp PARAGRAPH { ^(For the index above and WHERE clause like this: } CODE { ... WHERE a=5 AND b IN (1,2,3) AND c IS NULL AND d='hello' |