sl@0: /* sl@0: ** 2007 May 7 sl@0: ** sl@0: ** The author disclaims copyright to this source code. In place of sl@0: ** a legal notice, here is a blessing: sl@0: ** sl@0: ** May you do good and not evil. sl@0: ** May you find forgiveness for yourself and forgive others. sl@0: ** May you share freely, never taking more than you give. sl@0: ** sl@0: ************************************************************************* sl@0: ** sl@0: ** This file defines various limits of what SQLite can process. sl@0: ** sl@0: ** @(#) $Id: sqliteLimit.h,v 1.8 2008/03/26 15:56:22 drh Exp $ sl@0: */ sl@0: sl@0: /* sl@0: ** The maximum length of a TEXT or BLOB in bytes. This also sl@0: ** limits the size of a row in a table or index. sl@0: ** sl@0: ** The hard limit is the ability of a 32-bit signed integer sl@0: ** to count the size: 2^31-1 or 2147483647. sl@0: */ sl@0: #ifndef SQLITE_MAX_LENGTH sl@0: # define SQLITE_MAX_LENGTH 1000000000 sl@0: #endif sl@0: sl@0: /* sl@0: ** This is the maximum number of sl@0: ** sl@0: ** * Columns in a table sl@0: ** * Columns in an index sl@0: ** * Columns in a view sl@0: ** * Terms in the SET clause of an UPDATE statement sl@0: ** * Terms in the result set of a SELECT statement sl@0: ** * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement. sl@0: ** * Terms in the VALUES clause of an INSERT statement sl@0: ** sl@0: ** The hard upper limit here is 32676. Most database people will sl@0: ** tell you that in a well-normalized database, you usually should sl@0: ** not have more than a dozen or so columns in any table. And if sl@0: ** that is the case, there is no point in having more than a few sl@0: ** dozen values in any of the other situations described above. sl@0: */ sl@0: #ifndef SQLITE_MAX_COLUMN sl@0: # define SQLITE_MAX_COLUMN 2000 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum length of a single SQL statement in bytes. sl@0: ** sl@0: ** It used to be the case that setting this value to zero would sl@0: ** turn the limit off. That is no longer true. It is not possible sl@0: ** to turn this limit off. sl@0: */ sl@0: #ifndef SQLITE_MAX_SQL_LENGTH sl@0: # define SQLITE_MAX_SQL_LENGTH 1000000000 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum depth of an expression tree. This is limited to sl@0: ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might sl@0: ** want to place more severe limits on the complexity of an sl@0: ** expression. sl@0: ** sl@0: ** A value of 0 used to mean that the limit was not enforced. sl@0: ** But that is no longer true. The limit is now strictly enforced sl@0: ** at all times. sl@0: */ sl@0: #ifndef SQLITE_MAX_EXPR_DEPTH sl@0: # define SQLITE_MAX_EXPR_DEPTH 1000 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum number of terms in a compound SELECT statement. sl@0: ** The code generator for compound SELECT statements does one sl@0: ** level of recursion for each term. A stack overflow can result sl@0: ** if the number of terms is too large. In practice, most SQL sl@0: ** never has more than 3 or 4 terms. Use a value of 0 to disable sl@0: ** any limit on the number of terms in a compount SELECT. sl@0: */ sl@0: #ifndef SQLITE_MAX_COMPOUND_SELECT sl@0: # define SQLITE_MAX_COMPOUND_SELECT 500 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum number of opcodes in a VDBE program. sl@0: ** Not currently enforced. sl@0: */ sl@0: #ifndef SQLITE_MAX_VDBE_OP sl@0: # define SQLITE_MAX_VDBE_OP 25000 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum number of arguments to an SQL function. sl@0: */ sl@0: #ifndef SQLITE_MAX_FUNCTION_ARG sl@0: # define SQLITE_MAX_FUNCTION_ARG 100 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum number of in-memory pages to use for the main database sl@0: ** table and for temporary tables. The SQLITE_DEFAULT_CACHE_SIZE sl@0: */ sl@0: #ifndef SQLITE_DEFAULT_CACHE_SIZE sl@0: # define SQLITE_DEFAULT_CACHE_SIZE 2000 sl@0: #endif sl@0: #ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE sl@0: # define SQLITE_DEFAULT_TEMP_CACHE_SIZE 500 sl@0: #endif sl@0: sl@0: /* sl@0: ** The maximum number of attached databases. This must be between 0 sl@0: ** and 30. The upper bound on 30 is because a 32-bit integer bitmap sl@0: ** is used internally to track attached databases. sl@0: */ sl@0: #ifndef SQLITE_MAX_ATTACHED sl@0: # define SQLITE_MAX_ATTACHED 10 sl@0: #endif sl@0: sl@0: sl@0: /* sl@0: ** The maximum value of a ?nnn wildcard that the parser will accept. sl@0: */ sl@0: #ifndef SQLITE_MAX_VARIABLE_NUMBER sl@0: # define SQLITE_MAX_VARIABLE_NUMBER 999 sl@0: #endif sl@0: sl@0: /* Maximum page size. The upper bound on this value is 32768. This a limit sl@0: ** imposed by the necessity of storing the value in a 2-byte unsigned integer sl@0: ** and the fact that the page size must be a power of 2. sl@0: */ sl@0: #ifndef SQLITE_MAX_PAGE_SIZE sl@0: # define SQLITE_MAX_PAGE_SIZE 32768 sl@0: #endif sl@0: sl@0: sl@0: /* sl@0: ** The default size of a database page. sl@0: */ sl@0: #ifndef SQLITE_DEFAULT_PAGE_SIZE sl@0: # define SQLITE_DEFAULT_PAGE_SIZE 1024 sl@0: #endif sl@0: #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE sl@0: # undef SQLITE_DEFAULT_PAGE_SIZE sl@0: # define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE sl@0: #endif sl@0: sl@0: /* sl@0: ** Ordinarily, if no value is explicitly provided, SQLite creates databases sl@0: ** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain sl@0: ** device characteristics (sector-size and atomic write() support), sl@0: ** SQLite may choose a larger value. This constant is the maximum value sl@0: ** SQLite will choose on its own. sl@0: */ sl@0: #ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE sl@0: # define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192 sl@0: #endif sl@0: #if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE sl@0: # undef SQLITE_MAX_DEFAULT_PAGE_SIZE sl@0: # define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE sl@0: #endif sl@0: sl@0: sl@0: /* sl@0: ** Maximum number of pages in one database file. sl@0: ** sl@0: ** This is really just the default value for the max_page_count pragma. sl@0: ** This value can be lowered (or raised) at run-time using that the sl@0: ** max_page_count macro. sl@0: */ sl@0: #ifndef SQLITE_MAX_PAGE_COUNT sl@0: # define SQLITE_MAX_PAGE_COUNT 1073741823 sl@0: #endif sl@0: sl@0: /* sl@0: ** Maximum length (in bytes) of the pattern in a LIKE or GLOB sl@0: ** operator. sl@0: */ sl@0: #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH sl@0: # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000 sl@0: #endif