NAME

       wgdb - shared memory database library

SYNOPSIS

       [see Doc folder and http://whitedb.org for the full manual]

DESCRIPTION

       WhiteDB  is  a  lightweight  NoSQL  database library written in C, operating fully in main
       memory.  There is no server process. Data is read  and  written  directly  from/to  shared
       memory,  no  sockets are used between WhiteDB and the application program. All the data is
       accessible to separate processes.

       Each database record is a tuple of N elements, encoded in WhiteDB-s simple compact format.
       You  can  store  both  conventional  datatypes  and direct pointers to records: the latter
       enables highly efficient traversal of complex data.

       Each element is encoded as an integer: configurable as either 32 or 64 bits.  The integers
       in  the  tuple  encode  values directly or as pointers.  Columns have no type: any encoded
       value can be stored to any field.  You can always get a direct pointer to a record,  store
       it  into  a field of a record or use it in your own program directly. A record pointer can
       thus be used as an automatically assigned id of the record which requires no search at all
       to access the record.

       The low bits of an integer in a record indicate the type of data.  Anything which does not
       fit into the remainining bits is allocated separately and pointed to by the same integer.

       We use a database level lock  implemented  via  a  task-fair  atomic  spinlock  queue  for
       concurrency  control,  but  alternative  faster  and  simpler  preference  policies can be
       configured: either a reader-preference or a writer-preference spinlock.  We  provide  safe
       atomic updates of simple values without taking a write lock.

       The  simplest  index  provided  is  a  T-tree index on any field containing any mixture of
       objects (integers, strings, etc).  The index is automatically maintained when records  are
       added, deleted or changed.

       Two  mechanisms  are available for storing the shared memory database to disk.  First, the
       whole database can be dumped and restored.  Second, all inserts, deletions and updates can
       be logged to a file.

SEE ALSO

       The Whitedb web site can be found at:
                     http://whitedb.org

REPORTING PROBLEMS

       Please use either https://github.com/priitj/whitedb or email to authors.

AUTHORS

       Copyright    (C)    2008-2014    Tanel   Tammet   (tanel.tammet@gmail.com),   Priit   Järv
       (priit@whitedb.org)