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Overview
Comment: | When moving a page to make way for the root page of a new table or index in an auto-vacuum database, save the positions of any cursors that may be holding xFetch references to the page being moved. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | experimental-mmap |
Files: | files | file ages | folders |
SHA1: |
9d9b1da54a555e8fb6037d63d1952458 |
User & Date: | dan 2013-04-03 11:38:36.388 |
Context
2013-04-03
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11:52 | Remove the restriction on using xFetch to load the root pages of tables and indexes. It appears to have been based on a misconception. (check-in: 5b082efead user: dan tags: experimental-mmap) | |
11:38 | When moving a page to make way for the root page of a new table or index in an auto-vacuum database, save the positions of any cursors that may be holding xFetch references to the page being moved. (check-in: 9d9b1da54a user: dan tags: experimental-mmap) | |
11:17 | In btree.c, save the positions of other cursors open on the same table when writing via an incremental blob handle. Otherwise, they may be left holding an out-of-date xFetch page reference. (check-in: 3f09fba18f user: dan tags: experimental-mmap) | |
Changes
Changes to src/btree.c.
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7264 7265 7266 7267 7268 7269 7270 7271 7272 7273 7274 7275 7276 7277 | ** the new table (assuming an error did not occur). But we were ** allocated pgnoMove. If required (i.e. if it was not allocated ** by extending the file), the current page at position pgnoMove ** is already journaled. */ u8 eType = 0; Pgno iPtrPage = 0; releasePage(pPageMove); /* Move the page currently at pgnoRoot to pgnoMove. */ rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0); if( rc!=SQLITE_OK ){ return rc; | > > > > > > > > | 7264 7265 7266 7267 7268 7269 7270 7271 7272 7273 7274 7275 7276 7277 7278 7279 7280 7281 7282 7283 7284 7285 | ** the new table (assuming an error did not occur). But we were ** allocated pgnoMove. If required (i.e. if it was not allocated ** by extending the file), the current page at position pgnoMove ** is already journaled. */ u8 eType = 0; Pgno iPtrPage = 0; /* Save the positions of any open cursors. This is required in ** case they are holding a reference to an xFetch reference ** corresponding to page pgnoRoot. */ rc = saveAllCursors(pBt, 0, 0); if( rc!=SQLITE_OK ){ return rc; } releasePage(pPageMove); /* Move the page currently at pgnoRoot to pgnoMove. */ rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0); if( rc!=SQLITE_OK ){ return rc; |
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Changes to test/mmap1.test.
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201 202 203 204 205 206 207 | do_test 4.4 { sqlite3_finalize $::STMT } SQLITE_OK do_execsql_test 4.5 { COMMIT } | > > > > > > > > > > > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > | 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 | do_test 4.4 { sqlite3_finalize $::STMT } SQLITE_OK do_execsql_test 4.5 { COMMIT } #------------------------------------------------------------------------- # Ensure that existing cursors holding xFetch() references are not # confused if those pages are moved to make way for the root page of a # new table or index. # reset_db do_execsql_test 5.1 { PRAGMA auto_vacuum = 2; PRAGMA page_size = 1024; CREATE TABLE t1(x); INSERT INTO t1 VALUES($aaa); INSERT INTO t1 VALUES($bbb); INSERT INTO t1 VALUES($ccc); INSERT INTO t1 VALUES($ddd); PRAGMA auto_vacuum; SELECT * FROM t1; } [list 2 $aaa $bbb $ccc $ddd] do_test 5.2 { set ::STMT [sqlite3_prepare db "SELECT * FROM t1 ORDER BY rowid" -1 dummy] sqlite3_step $::STMT sqlite3_column_text $::STMT 0 } $aaa do_execsql_test 5.3 { CREATE TABLE t2(x); INSERT INTO t2 VALUES('tricked you!'); INSERT INTO t2 VALUES('tricked you!'); } do_test 5.4 { sqlite3_step $::STMT sqlite3_column_text $::STMT 0 } $bbb do_test 5.5 { sqlite3_finalize $::STMT } SQLITE_OK finish_test |