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Comment:Leave unspecified what it means for the sqlite_stat3 and sqlite_stat4 tables to have idx columns equal to their tbl column.
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SHA1: c538b41b9103463b25e1cc2b22a4d9de69be0830
User & Date: drh 2013-09-19 14:24:33
Context
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
14:14
Fix typos and enhance the text of documentation for 3.8.1 changes. check-in: 1d0df412df user: drh tags: trunk
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Changes to pages/fileformat2.in.

  1253   1253   <blockquote><pre>
  1254   1254   CREATE TABLE sqlite_stat3(tbl,idx,nEq,nLt,nDLt,sample);
  1255   1255   </pre></blockquote>
  1256   1256   
  1257   1257   <p>There are usually multiple entries in the sqlite_stat3 table for each index.
  1258   1258   The sqlite_stat3.sample column holds the value of the left-most field of an
  1259   1259   index identified by sqlite_stat3.idx and sqlite_stat3.tbl.
  1260         -If the sqlite_stat3.idx and sqlite_stat3.tbl
  1261         -columns hold the same value, then that row contains a sample from
  1262         -the [INTEGER PRIMARY KEY] of the table.
  1263   1260   The sqlite_stat3.nEq column holds the approximate
  1264   1261   number of entries in the index whose left-most column exactly matches
  1265   1262   the sample.  
  1266   1263   The sqlite_stat3.nLt holds the approximate number of entries in the
  1267   1264   index whose left-most column is less than the sample.
  1268   1265   The sqlite_stat3.nDLt column holds the approximate
  1269   1266   number of distinct left-most entries in the index that are less than
................................................................................
  1290   1287   CREATE TABLE sqlite_stat4(tbl,idx,nEq,nLt,nDLt,sample);
  1291   1288   </pre></blockquote>
  1292   1289   
  1293   1290   <p>There are usually multiple entries in the sqlite_stat4 table for each index.
  1294   1291   The sqlite_stat4.sample column holds the content of an index entry in
  1295   1292   the [record format].  The index entry stored is taken from the
  1296   1293   index identified by sqlite_stat4.idx and sqlite_stat4.tbl.
  1297         -If sqlite_stat4.idx and sqlite_stat4.tbl
  1298         -hold the same value, then that row contains a sample from
  1299         -the [INTEGER PRIMARY KEY] of the table.
  1300   1294   The sqlite_stat4.nEq column holds a list of integers where the K-th integer
  1301   1295   is the approximate number of entries in the index whose left-most K columns
  1302   1296   exactly match the K left-most columns of the sample.
  1303   1297   The sqlite_stat4.nLt holds a list of integers where the K-th integer is
  1304   1298   the approximate number of entries in the
  1305   1299   index whose K left-most columns are collectively less than the 
  1306   1300   K left-most columns of the sample.