Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Clarification of the meaning of the stat column in sqlite_stat1. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
83b2bf0c4d3811e788aa22fa2fb2d0b2 |
| User & Date: | drh 2013-09-19 14:30:37.229 |
Context
|
2013-09-30
| ||
| 12:10 | Fix to the releaselog/current.html generator. (check-in: e7d9c2101a user: drh tags: trunk) | |
|
2013-09-19
| ||
| 14:30 | Clarification of the meaning of the stat column in sqlite_stat1. (check-in: 83b2bf0c4d user: drh tags: trunk) | |
| 14:24 | Leave unspecified what it means for the sqlite_stat3 and sqlite_stat4 tables to have idx columns equal to their tbl column. (check-in: c538b41b91 user: drh tags: trunk) | |
Changes
Changes to pages/fileformat2.in.
| ︙ | ︙ | |||
1173 1174 1175 1176 1177 1178 1179 | </pre></blockquote> <p>There is normally one row per index, with the index identified by the name in the sqlite_stat1.idx column. The sqlite_stat1.tbl column is the name of the table to which the index belongs. In each such row, the sqlite_stat.stat column will be a string consisting of a list of integers. The first integer in this | | | | | | > | > | | 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 |
</pre></blockquote>
<p>There is normally one row per index, with the index identified by the
name in the sqlite_stat1.idx column. The sqlite_stat1.tbl column is
the name of the table to which the index belongs. In each such row,
the sqlite_stat.stat column will be
a string consisting of a list of integers. The first integer in this
list is the approximate number of rows in the index and in the table.
The second integer is the approximate average number of rows in the index
that have the same value in the first column of the index. The third
integer is the approximate average number of rows in the index that have
the same value for the first two columns. The N-th integer (for N>1)
is the approximate average number of rows in
the index which have the same value for the first N-1 columns. For
a K-column index, there will be K+1 integers in the stat column. If
the index is unique, then the last integer will be 1.
<p>The list of integers in the stat column can optionally be followed
by the keyword "unordered". The "unordered" keyword, if it is present,
must be separated from the last integer by a single space. If the
"unordered" keyword is present, then the query planner assumes that
the index is unordered and will not use the index for a range query
or for sorting.
<p>If the sqlite_stat1.idx column is NULL, then the sqlite_stat1.stat
column contains a single integer which is the approximate number of
rows in the table identified by sqlite_stat1.tbl.
<tcl>hd_fragment stat2tab {sqlite_stat2}</tcl>
<h4>2.5.4 The sqlite_stat2 table</h4>
<p>The sqlite_stat2 is only created and is only used if SQLite is compiled
with SQLITE_ENABLE_STAT2 and if the SQLite version number is between
|
| ︙ | ︙ |