/*** 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 means that there is no limit.*/#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 compound 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 250000000#endif/*** The maximum number of arguments to an SQL function.*/#ifndef SQLITE_MAX_FUNCTION_ARG# define SQLITE_MAX_FUNCTION_ARG 127#endif/*** The suggested maximum number of in-memory pages to use for** the main database table and for temporary tables.**** IMPLEMENTATION-OF: R-30185-15359 The default suggested cache size is -2000,** which means the cache size is limited to 2048000 bytes of memory.** IMPLEMENTATION-OF: R-48205-43578 The default suggested cache size can be** altered using the SQLITE_DEFAULT_CACHE_SIZE compile-time options.*/#ifndef SQLITE_DEFAULT_CACHE_SIZE# define SQLITE_DEFAULT_CACHE_SIZE -2000#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 125. The upper bound of 125 is because the attached databases are** counted using a signed 8-bit integer which has a maximum value of 127** and we have to allow 2 extra counts for the "main" and "temp" databases.*/#ifndef SQLITE_MAX_ATTACHED# define SQLITE_MAX_ATTACHED 10#endif/*** The maximum value of a ?nnn wildcard that the parser will accept.** If the value exceeds 32767 then extra space is required for the Expr** structure. But otherwise, we believe that the number can be as large** as a signed 32-bit integer can hold.*/#ifndef SQLITE_MAX_VARIABLE_NUMBER# define SQLITE_MAX_VARIABLE_NUMBER 32766#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 4096#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 0xfffffffe /* 4294967294 */#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
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