/* ** 2007 May 7 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** This file defines various limits of what SQLite can process. */ /* ** The maximum length of a TEXT or BLOB in bytes. This also ** limits the size of a row in a table or index. ** ** The hard limit is the ability of a 32-bit signed integer ** to count the size: 2^31-1 or 2147483647. */ #ifndef SQLITE_MAX_LENGTH # define SQLITE_MAX_LENGTH 1000000000 #endif /* ** This is the maximum number of ** ** * Columns in a table ** * Columns in an index ** * Columns in a view ** * Terms in the SET clause of an UPDATE statement ** * Terms in the result set of a SELECT statement ** * Terms in the GROUP BY or ORDER BY clauses of a SELECT statement. ** * Terms in the VALUES clause of an INSERT statement ** ** The hard upper limit here is 32676. Most database people will ** tell you that in a well-normalized database, you usually should ** not have more than a dozen or so columns in any table. And if ** that is the case, there is no point in having more than a few ** dozen values in any of the other situations described above. */ #ifndef SQLITE_MAX_COLUMN # define SQLITE_MAX_COLUMN 2000 #endif /* ** The maximum length of a single SQL statement in bytes. ** ** It used to be the case that setting this value to zero would ** turn the limit off. That is no longer true. It is not possible ** to turn this limit off. */ #ifndef SQLITE_MAX_SQL_LENGTH # define SQLITE_MAX_SQL_LENGTH 1000000000 #endif /* ** The maximum depth of an expression tree. This is limited to ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might ** want to place more severe limits on the complexity of an ** expression. ** ** A value of 0 used to mean that the limit was not enforced. ** But that is no longer true. The limit is now strictly enforced ** at all times. */ #ifndef SQLITE_MAX_EXPR_DEPTH # define SQLITE_MAX_EXPR_DEPTH 1000 #endif /* ** The maximum number of terms in a compound SELECT statement. ** The code generator for compound SELECT statements does one ** level of recursion for each term. A stack overflow can result ** if the number of terms is too large. In practice, most SQL ** never has more than 3 or 4 terms. Use a value of 0 to disable ** any limit on the number of terms in a compount SELECT. */ #ifndef SQLITE_MAX_COMPOUND_SELECT # define SQLITE_MAX_COMPOUND_SELECT 500 #endif /* ** The maximum number of opcodes in a VDBE program. ** Not currently enforced. */ #ifndef SQLITE_MAX_VDBE_OP # define SQLITE_MAX_VDBE_OP 25000 #endif /* ** The maximum number of arguments to an SQL function. */ #ifndef SQLITE_MAX_FUNCTION_ARG # define SQLITE_MAX_FUNCTION_ARG 127 #endif /* ** The maximum number of in-memory pages to use for the main database ** table and for temporary tables. The SQLITE_DEFAULT_CACHE_SIZE */ #ifndef SQLITE_DEFAULT_CACHE_SIZE # define SQLITE_DEFAULT_CACHE_SIZE 2000 #endif #ifndef SQLITE_DEFAULT_TEMP_CACHE_SIZE # define SQLITE_DEFAULT_TEMP_CACHE_SIZE 500 #endif /* ** The default number of frames to accumulate in the log file before ** checkpointing the database in WAL mode. */ #ifndef SQLITE_DEFAULT_WAL_AUTOCHECKPOINT # define SQLITE_DEFAULT_WAL_AUTOCHECKPOINT 1000 #endif /* ** The maximum number of attached databases. This must be between 0 ** and 62. The upper bound on 62 is because a 64-bit integer bitmap ** is used internally to track attached databases. */ #ifndef SQLITE_MAX_ATTACHED # define SQLITE_MAX_ATTACHED 10 #endif /* ** The maximum value of a ?nnn wildcard that the parser will accept. */ #ifndef SQLITE_MAX_VARIABLE_NUMBER # define SQLITE_MAX_VARIABLE_NUMBER 999 #endif /* Maximum page size. The upper bound on this value is 65536. This a limit ** imposed by the use of 16-bit offsets within each page. ** ** Earlier versions of SQLite allowed the user to change this value at ** compile time. This is no longer permitted, on the grounds that it creates ** a library that is technically incompatible with an SQLite library ** compiled with a different limit. If a process operating on a database ** with a page-size of 65536 bytes crashes, then an instance of SQLite ** compiled with the default page-size limit will not be able to rollback ** the aborted transaction. This could lead to database corruption. */ #ifdef SQLITE_MAX_PAGE_SIZE # undef SQLITE_MAX_PAGE_SIZE #endif #define SQLITE_MAX_PAGE_SIZE 65536 /* ** The default size of a database page. */ #ifndef SQLITE_DEFAULT_PAGE_SIZE # define SQLITE_DEFAULT_PAGE_SIZE 1024 #endif #if SQLITE_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE # undef SQLITE_DEFAULT_PAGE_SIZE # define SQLITE_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE #endif /* ** Ordinarily, if no value is explicitly provided, SQLite creates databases ** with page size SQLITE_DEFAULT_PAGE_SIZE. However, based on certain ** device characteristics (sector-size and atomic write() support), ** SQLite may choose a larger value. This constant is the maximum value ** SQLite will choose on its own. */ #ifndef SQLITE_MAX_DEFAULT_PAGE_SIZE # define SQLITE_MAX_DEFAULT_PAGE_SIZE 8192 #endif #if SQLITE_MAX_DEFAULT_PAGE_SIZE>SQLITE_MAX_PAGE_SIZE # undef SQLITE_MAX_DEFAULT_PAGE_SIZE # define SQLITE_MAX_DEFAULT_PAGE_SIZE SQLITE_MAX_PAGE_SIZE #endif /* ** Maximum number of pages in one database file. ** ** This is really just the default value for the max_page_count pragma. ** This value can be lowered (or raised) at run-time using that the ** max_page_count macro. */ #ifndef SQLITE_MAX_PAGE_COUNT # define SQLITE_MAX_PAGE_COUNT 1073741823 #endif /* ** Maximum length (in bytes) of the pattern in a LIKE or GLOB ** operator. */ #ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH # define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000 #endif /* ** Maximum depth of recursion for triggers. ** ** A value of 1 means that a trigger program will not be able to itself ** fire any triggers. A value of 0 means that no trigger programs at all ** may be executed. */ #ifndef SQLITE_MAX_TRIGGER_DEPTH # define SQLITE_MAX_TRIGGER_DEPTH 1000 #endif