Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.
|Comment:||Leave unspecified what it means for the sqlite_stat3 and sqlite_stat4 tables to have idx columns equal to their tbl column.|
|Timelines:||family | ancestors | descendants | both | trunk|
|Files:||files | file ages | folders|
|User & Date:||drh 2013-09-19 14:24:33|
|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|
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.