# opendb

> ## Directory

> > eXtremeDB_rt/samples/opendb

> ## Description

> > Demonstrates opening a database using a conventional memory device.

> ## Used API

> > mco_db_open_dev()

> ## Code snippet

> >        /* Setup database memory device as a plain conventional memory region */
> >          dev.type       = MCO_MEMORY_CONV;                /* Set the device as a conventional memory device */
> >          dev.assignment = MCO_MEMORY_ASSIGN_DATABASE;     /* Assign the device as main database memory */
> >          dev.size       = DATABASE_SEGMENT_SIZE;          /* Set the device size */
> >          dev.dev.conv.ptr = (char*)malloc( dev.size ); /* Allocate memory and set device pointer */

> >           /* Initialize and customize the database parameters */
> >           mco_db_params_init ( &db_params );               /* Initialize the params with
> >          default values */

> >           db_params.mem_page_size      = MEMORY_PAGE_SIZE; /* Set page size for the in-memory part */
> >           db_params.disk_page_size     = 0;                /* Set page size to zero to disable disk operations */
> >           db_params.db_max_connections = 1;                /* Set total number of connections to the database */

> >           /* Open a database on the device with given params */
> >           rc = mco_db_open_dev(db_name, convdb_get_dictionary(), dev, 2, &db_params );
> >           if ( MCO_S_OK == rc ) {

> ## What to expect as an output

> >         ./target/bin/opendb

> >         Initialize MCO runtime : Successful
> >         Sample 'dbopen' opens a database using conventional memory.

> >         eXtremeDB/rt runtime version 1.4,  Debug
> >         Copyright (c) 2001-2024 McObject LLC. All Rights Reserved.

> >         	Open database : Successful

> >         	The opened database has the following characteristics:

> >         	Evaluation runtime ______ : no
> >         	Check-level _____________ : 3
> >         	Multithread support _____ : yes
> >         	Fixedrec support ________ : yes
> >         	Shared memory support ___ : no
> >         	Statistics support ______ : yes
> >         	Events support __________ : yes
> >         	Save/Load support _______ : yes
> >         	RTree index support _____ : yes
> >         	Unicode support _________ : yes
> >         	WChar support ___________ : no
> >         	Persistent storage support: no
> >         	Direct pointers mode ____ : no

> >         	Close database : Successful