diff --git a/man3/hash.3 b/man3/hash.3 index 1ef5d7195..5141a0196 100644 --- a/man3/hash.3 +++ b/man3/hash.3 @@ -73,46 +73,41 @@ typedef struct { .in .PP The elements of this structure are as follows: -.TP -bsize -.I Bsize +.TP 10 +.I bsize defines the hash table bucket size, and is, by default, 256 bytes. It may be preferable to increase the page size for disk-resident tables and tables with large data items. .TP -ffactor -.I Ffactor +.I ffactor indicates a desired density within the hash table. It is an approximation of the number of keys allowed to accumulate in any one bucket, determining when the hash table grows or shrinks. The default value is 8. .TP -nelem -.I Nelem +.I nelem is an estimate of the final size of the hash table. If not set or set too low, hash tables will expand gracefully as keys are entered, although a slight performance degradation may be noticed. The default value is 1. .TP -cachesize -A suggested maximum size, in bytes, of the memory cache. +.I cachesize +is the suggested maximum size, in bytes, of the memory cache. This value is -.B only -advisory, and the access method will allocate more memory rather -than fail. +.IR "only advisory" , +and the access method will allocate more memory rather than fail. .TP -hash -.I Hash +.I hash is a user defined hash function. Since no hash function performs equally well on all possible data, the user may find that the built-in hash function does poorly on a particular data set. -User specified hash functions must take two arguments (a pointer to a byte +A user-specified hash functions must take two arguments (a pointer to a byte string and a length) and return a 32-bit quantity to be used as the hash value. .TP -lorder -The byte order for integers in the stored database metadata. +.I lorder +is the byte order for integers in the stored database metadata. The number should represent the order as an integer; for example, big endian order would be the number 4,321. If @@ -124,7 +119,13 @@ value specified when the tree was created is used. If the file already exists (and the .B O_TRUNC flag is not specified), the -values specified for the parameters bsize, ffactor, lorder and nelem are +values specified for the parameters +.IR bsize , +.IR ffactor , +.IR lorder , +and +.I nelem +are ignored and the values specified when the tree was created are used. .PP If a hash function is specified, @@ -146,7 +147,7 @@ access method routines may fail and set for any of the errors specified for the library routine .BR dbopen (3). .SH BUGS -Only big and little endian byte order is supported. +Only big and little endian byte order are supported. .SH "SEE ALSO" .BR btree (3), .BR dbopen (3),