Physical Database File Storage
In This Topic
Large Storage Capacity
VistaDB databases support up to 4TB of data with 64,000 tables, 1,024 indexes per table and 4 billion rows per table. Additional storage capacity includes 4GB of data per row, individual Varchar(Max) fields can store up to 4GB of data per row (see pagesize limits), millions of columns per table and over 1,000 indexes per table.
The current implementation is limited in practice by the hardware of the machine and limits imposed by the OS. For example it's infeasible to put a 2 TB database on a machine with 512 MB of RAM. There are no hard limits enforced by the engine; it's recommended that your application be tested to see if your targeted environment can handle the size of your data. The schema of the database, table schema, and indexes will change the footprint for each application..
There can also be limits based on the CPU mode your application is running in. If the hosting application is built as a 32 bit EXE the database will also load in 32 bit mode. In this mode there is only 1.5 GB of memory available for data in the entire process (including all Virtual Memory). This means that VistaDB usually has a much smaller area for RAM due to other memory being used within your process.
Unicode Support
VistaDB allows developers to build internationalized applications that support single and double byte character sets through our extensive Unicode support. In general, VistaDB supports the same UNICODE flexibility as SQL Server.
Column Attributes
- Identity column types are supported, which provide auto-increment support for new rows with start and increment settings.
- Other attributes include marking columns as part of the table's Primary Key, allowing NULL values, marking columns as read-only, encrypting individual columns and marking columns to be indexed. And default values can be set for new and updated rows.
Encryption
VistaDB databases can be encrypted using FIPS-compliant AES encryption. When encrypted, the entire database including data, schema, and procedures is encrypted.
High-Speed Indexes
VistaDB allows you to create multiple types of high-speed indexes:
- Primary Key indexes can consist of one or more columns to define a unique identifying value for each row.
- Standard indexes can consist of or more columns
- Full-Text Search (FTS) indexes may be made up of more than one column and allow for high-speed single term searching of text within Text, NText, VarChar, NVarChar, NChar and Char columns.
Additional Database Features
- Constraints can be defined to ensure that only valid data values are entered into the database.
- Relationships help ensure the integrity of a database by letting you define Foreign Keys between tables.
- CLR Triggers can be used to call your custom CLR code when certain conditions happen in the database.
- CLR Procs can call your custom assembly for additional stored procedure functionality.
- TSQL Procs can be used as SQL scripts within your application and are stored within the database file.
See Also