The Schema file begins with optional storage format options:
HashSize = <Number>:
Sets the number of buckets in the HashTable file.
If you leave this number out, Qddb will use a default of 20,000.
HashType = <Number>:
Sets the hash function to <Number>, where <Number>
may currently be 0 or 1. 0 is the default
hash function; 1 is a newer function designed for data with
repetitive prefixes/suffixes. If your data contains
numbers, WWW URLs, or source code, you may find that HashType
1 performs much better than the default. You can experiment
with your own HashType by editing the function Qddb_HashValue
in Lib/LibQddb/Hash.c.
Use Cached Hashing:
Instructs qstall and qindex to build a HashTable file
suitable
for caching hash values instead of reading the entire file at startup.
CacheSize = <Number>:
Sets the maximum number of hash values to cache.
Ignored unless ``Use Cached Hashing'' is specified.
Use Reduced Attribute Identifiers:
Instructs qstall to build a RedAttrIndex structure file
holding the full attribute identifiers.
This option reduces the size of the Database and Index
files, because the lengthy attribute identifiers and instance numbers
are represented by a shorter base-36 number. You can add and delete
this option from the Schema at any time, but you must
immediately restabilize with qstall. qstall will notice
that you are converting from reduced attribute identifiers to full attribute
identifiers (or vice-versa) and make the appropriate conversion.
DateFormat = "Format String":
Sets the default format string for outputting dates (this relation only).
Any format suitable for strftime(3) is allowed.
Use Cached Secondary Search: This option
significantly speeds up the searching of the instable parts of
the database at the expense of some memory and an extra
lookaside file "SecondaryCache" (see the Schema.5 man page)
Use ExcludeWords: Instructs Qddb to read the file ``ExcludeWords''
for words that should be excluded from the index files. Searching for
words contained in this file will yield ``No matches found.''
since the words are omitted from the index files.