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Overview
Comment: | Updates to the PRAGMA documentation. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
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b5201ace8f761b5a8a8ded9c889dac0e |
User & Date: | drh 2010-11-23 15:57:02.000 |
Context
2010-11-26
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15:18 | Further updates to pragma documentation. Mark deprecated pragmas as such. Tag pragmas used for debugging only. (check-in: e3dca045a2 user: drh tags: trunk) | |
2010-11-23
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15:57 | Updates to the PRAGMA documentation. (check-in: b5201ace8f user: drh tags: trunk) | |
2010-11-21
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01:36 | Updates to documentation on date/time functions and pragmas. (check-in: 2d231c8139 user: drh tags: trunk) | |
Changes
Changes to pages/pragma.in.
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198 199 200 201 202 203 204 | } Pragma checkpoint_fullfsync { <p>^(<b>PRAGMA checkpoint_fullfsync <br>PRAGMA checkpoint_fullfsync = </b><i>boolean</i><b>;</b></p> <p>Query or change the fullfsync flag for [checkpoint] operations.)^ ^If this flag is set, then the F_FULLFSYNC syncing method is used | | | | | 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | } Pragma checkpoint_fullfsync { <p>^(<b>PRAGMA checkpoint_fullfsync <br>PRAGMA checkpoint_fullfsync = </b><i>boolean</i><b>;</b></p> <p>Query or change the fullfsync flag for [checkpoint] operations.)^ ^If this flag is set, then the F_FULLFSYNC syncing method is used during checkpoint operations on systems that support F_FULLFSYNC. ^The default value of the checkpoint_fullfsync flag is off. Only Mac OS-X supports F_FULLFSYNC.</p> <p>^If the [fullfsync] flag is set, then the F_FULLFSYNC syncing method is used for all sync operations and the checkpoint_fullfsync setting is irrelevant.</p> } Pragma count_changes { <p>^(<b>PRAGMA count_changes; <br>PRAGMA count_changes = </b>boolean</i><b>;</b></p> |
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275 276 277 278 279 280 281 | <p>^In first form, if the main database has already been created, then this pragma returns the text encoding used by the main database, one of "UTF-8", "UTF-16le" (little-endian UTF-16 encoding) or "UTF-16be" (big-endian UTF-16 encoding). ^If the main database has not already been created, then the value returned is the text encoding that will be used to create the main database, if it is created by this session.</p> | | | | | | | | > | 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 | <p>^In first form, if the main database has already been created, then this pragma returns the text encoding used by the main database, one of "UTF-8", "UTF-16le" (little-endian UTF-16 encoding) or "UTF-16be" (big-endian UTF-16 encoding). ^If the main database has not already been created, then the value returned is the text encoding that will be used to create the main database, if it is created by this session.</p> <p>^The second through fifth forms of this pragma set the encoding that the main database will be created with if it is created by this session. ^The string "UTF-16" is interpreted as "UTF-16 encoding using native machine byte-ordering". ^It is not possible to change the text encoding of a database after it has been created and any attempt to do so will be silently ignored.</p> <p>^Once an encoding has been set for a database, it cannot be changed.</p> <p>^Databases created by the [ATTACH] command always use the same encoding as the main database. ^An attempt to [ATTACH] a database with a different text encoding from the "main" database will fail.</p> } Pragma foreign_keys { <p>^(<b>PRAGMA foreign_keys; <br>PRAGMA foreign_keys = </b><i>boolean</i><b>;</b></p> <p>Query, set, or clear the enforcement of [foreign key constraints].)^ |
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589 590 591 592 593 594 595 | SQLITE_DEFALT_PAGE_SIZE and the sector size as reported by the xSectorSize method of the [sqlite3_io_methods] object, but not more than SQLITE_MAX_DEFAULT_PAGE_SIZE. ^The normal configuration for SQLite running on workstations is for atomic write to be disabled, for the maximum page size to be set to 65536, for SQLITE_DEFAULT_PAGE_SIZE to be 1024, and for the | | | | > > > | 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 | SQLITE_DEFALT_PAGE_SIZE and the sector size as reported by the xSectorSize method of the [sqlite3_io_methods] object, but not more than SQLITE_MAX_DEFAULT_PAGE_SIZE. ^The normal configuration for SQLite running on workstations is for atomic write to be disabled, for the maximum page size to be set to 65536, for SQLITE_DEFAULT_PAGE_SIZE to be 1024, and for the maximum default page size to be set to 8192. The default xSectorSize method on unix workstation implementations always reports a sector size of 512 bytes. Hence, the default page size chosen by SQLite on unix is usually 1024 bytes. On windows, the GetDiskFreeSpace() interface is used to obtain the actual device sector size and hence the default page size on windows will sometimes be greater than 1024.</p> } Pragma max_page_count { <p>^(<b>PRAGMA max_page_count; <br>PRAGMA max_page_count = </b><i>N</i><b>;</b></p> <p>Query or set the maximum number of pages in the database file.)^ ^Both forms of the pragma return the maximum page count. ^The second |
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897 898 899 900 901 902 903 | <p><b>PRAGMA schema_version; <br>PRAGMA schema_version = </b><i>integer </i><b>; <br>PRAGMA user_version; <br>PRAGMA user_version = </b><i>integer </i><b>;</b> <p> ^The pragmas schema_version and user_version are used to set or get | | | | > | | 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 | <p><b>PRAGMA schema_version; <br>PRAGMA schema_version = </b><i>integer </i><b>; <br>PRAGMA user_version; <br>PRAGMA user_version = </b><i>integer </i><b>;</b> <p> ^The pragmas schema_version and user_version are used to set or get the value of the schema-version and user-version, respectively. ^(The schema-version and the user-version are big-endian 32-bit signed integers stored in the database header at offsets 40 and 60, respectively.)^</p> <p> ^(The schema-version is usually only manipulated internally by SQLite. It is incremented by SQLite whenever the database schema is modified (by creating or dropping a table or index).)^ ^The schema version is used by SQLite each time a query is executed to ensure that the internal cache of the schema used when compiling the SQL query matches the schema of the database against which the compiled query is actually executed. ^Subverting this mechanism by using "PRAGMA schema_version" to modify the schema-version is potentially dangerous and may lead to program crashes or database corruption. Use with caution!</p> <p> The user-version is not used internally by SQLite. It may be used by applications for any purpose.</p> } Pragma compile_options { <p><b>PRAGMA compile_options;</b></p> <p>^This pragma returns the names of [compile-time options] used when building SQLite, one option per row. ^The "SQLITE_" prefix is omitted |
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951 952 953 954 955 956 957 | integrity_check. Otherwise the two pragmas are the same. </p> } Pragma parser_trace { <p><b>PRAGMA parser_trace = </b><i>boolean</i><b>; </b></p> | < < | < | | < | | > > | < < < < > > | > | < < < < | 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 | integrity_check. Otherwise the two pragmas are the same. </p> } Pragma parser_trace { <p><b>PRAGMA parser_trace = </b><i>boolean</i><b>; </b></p> <p>If SQLite has been compiled with the [SQLITE_DEBUG] compile-time option, then the parser_trace pragma can be used to turn on tracing of the SQL parser used internally by SQLite. This feature is used for debugging SQLite itself.</p> } Pragma vdbe_trace { <p><b>PRAGMA vdbe_trace = </b><i>boolean</i><b>;</b></p> <p>If SQLite has been compiled with the [SQLITE_DEBUG] compile-time option, then the vdbe_trace pragma can be used to cause virtual machine opcodes to be printed on standard output as they are evaluated. This feature is used for debugging SQLite. See the <a href="vdbe.html#trace">VDBE documentation</a> for more information.</p> } Pragma vdbe_listing { <p><b>PRAGMA vdbe_listing = </b><i>boolean</i><b>;</b></p> <p>If SQLite has been compiled with the [SQLITE_DEBUG] compile-time option, then the vdbe_listing pragma can be used to cause a complete listing of the virtual machine opcodes to appear on standard output as each statement is evaluated. With listing is on, the entire content of a program is printed just prior to beginning execution. The statement executes normally after the listing is printed. This feature is used for debugging SQLite itself. See the <a href="vdbe.html#trace">VDBE documentation</a> for more information.</p> } Pragma wal_checkpoint { <p><b>PRAGMA </b><i>database</i><b>.wal_checkpoint;</b></p> <p>^If the [write-ahead log] is enabled (via the [journal_mode pragma]), this pragma causes a checkpoint operation to run on database |
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Changes to pages/support.in.
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8 9 10 11 12 13 14 | <p> If you would like professional support for SQLite or if you want custom modifications performed by the original author of SQLite, these services are available for a modest fee. For additional information visit [http://www.hwaci.com/sw/sqlite/prosupport.html] or contact:</p> | | > > > > > | | 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | <p> If you would like professional support for SQLite or if you want custom modifications performed by the original author of SQLite, these services are available for a modest fee. For additional information visit [http://www.hwaci.com/sw/sqlite/prosupport.html] or contact:</p> <table border="0" cellpadding="15"> <tr><td valign="top"> D. Richard Hipp <br /> Hwaci - Applied Software Research <br /> 704.948.4565 <br /> <a href="mailto:drh@hwaci.com">drh@hwaci.com</a> </td><td valign="top"> <form method="GET" action="http://www.hwaci.com/sw/sqlite/prosupport.html"> <input type="submit" value="More Info"></form> </td></tr> </table> <h3>Proprietary SQLite Extensions</h3> <p>The core SQLite library found on this website is in the <a href="copyright.html">public domain</a>. But there also exist proprietary, licensed extensions to SQLite, written and maintained by the original developer.</p> |
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