Introduction
In this article, I want to tell you about undocumented system tables
shipped with SQL Server 2000. These tables are used by some system
stored procedures and stored in the master database (only sysfiles1,
sysproperties and sysfulltextnotify system tables are stored in each
database).
Undocumented System Tables
syscursorcolumns
Contains the list of server cursor's columns. This table is stored
in the master database. syscursorcolumns table is used by
sp_describe_cursor_columns system stored procedure to report the
attributes of the columns in the result set of a server cursor.
| Column name | Data type | Description |
|---|---|---|
| cursor_handle | int | A unique value for the cursor within the scope of the server. |
| column_name | sysname, nullable | The column name. The column is NULL if the column was specified without an accompanying AS clause. |
| ordinal_position | int | Relative position of the column. The first column is in position 1. The value for any hidden columns is 0. |
| column_characteristics_flags | int | A bitmask indicating the information stored in DBCOLUMNFLAGS in OLE DB. Can be one of the following: 1 = Bookmark 2 = Fixed length 4 = Nullable 8 = Row versioning 16 = Updatable column (set for projected columns of a cursor that has no FOR UPDATE clause and, if there is such a column, can be only one per cursor). |
| column_size | int | Maximum possible size for a value in this column. |
| data_type_sql | smallint | Number indicating the SQL Server data type of the column. |
| column_precision | tinyint | Maximum precision of the column as per the bPrecision value in OLE DB. |
| column_scale | tinyint | Number of digits to the right of the decimal point for the numeric or decimal data types as per the bScale value in OLE DB. |
| order_position | int | If the column participates in the ordering of the result set, the position of the column in the order key relative to the leftmost column. |
| order_direction | varchar(1), nullable | A = The column is in the order key and the ordering is ascending. D = The column is in the order key and the ordering is descending. NULL = The column does not participate in ordering. |
| hidden_column | smallint | If a value of 0, this column appears in the select list. The value 1 is reserved for future use. |
| columnid | int | Column ID of the base column. If the result set column was built from an expression, columnid is -1. |
| objectid | int | Object ID of the base table supplying the column. If the result set column was built from an expression, objectid is -1. |
| dbid | int | ID of the database containing the base table supplying the column. If the result set column was built from an expression, dbid is -1. |
| dbname | sysname, nullable | Name of the database containing the base table supplying the column. If the result set column was built from an expression, dbname is NULL. |
syscursorrefs
Contains one row for each server cursor. This table is stored in the
master database and contains cursor name, cursor scope (local
or global) and cursor handler. syscursorrefs table is used by
sp_describe_cursor, sp_describe_cursor_columns,
sp_describe_cursor_tables and sp_cursor_list system
stored procedures to get cursor name, cursor scope and cursor handler.
| Column name | Data type | Description |
|---|---|---|
| reference_name | sysname, nullable | Name used to refer to the cursor. |
| cursor_scope | tinyint | 1 = LOCAL 2 = GLOBAL |
| cursor_handl | int | A unique value for the cursor within the scope of the server. |
syscursors
Contains the attributes of a server cursor. This table is stored in the
master database. syscursors table is used by
sp_describe_cursor system stored procedures to report the attributes
of a server cursor and by sp_cursor_list system stored procedures to
report the attributes of server cursors currently open for the connection.
| Column name | Data type | Description |
|---|---|---|
| cursor_handle | int | A unique value for the cursor within the scope of the server. |
| cursor_name | sysname, nullable | Name of the cursor. |
| status | int | Same values as reported by the CURSOR_STATUS system function: 1 = The cursor referenced by the cursor name or variable is open. If the cursor is insensitive, static, or keyset, it has at least one row. If the cursor is dynamic, the result set has zero or more rows. 0 = The cursor referenced by the cursor name or variable is open but has no rows. Dynamic cursors never return this value. -1 = The cursor referenced by the cursor name or variable is closed. -2 = Applies only to cursor variables. There is no cursor assigned to the variable. Possibly, an OUTPUT parameter assigned a cursor to the variable, but the stored procedure closed the cursor before returning. -3 = A cursor or cursor variable with the specified name does not exist, or the cursor variable has not had a cursor allocated to it. |
| model | tinyint | 1 = Insensitive (or static) 2 = Keyset 3 = Dynamic 4 = Fast Forward |
| concurrency | tinyint | 1 = Read-only 2 = Scroll locks 3 = Optimistic |
| scrollable | tinyint | 0 = Forward-only 1 = Scrollable |
| open_status | tinyint | 0 = Closed 1 = Open |
| cursor_rows | decimal(10,0) | Number of qualifying rows in the result set. |
| fetch_status | smallint | Status of the last fetch on this cursor. 0 = Fetch successful. -1 = Fetch failed or is beyond the bounds of the cursor. -2 = The requested row is missing. -9 = There has been no fetch on the cursor. |
| column_count | smallint | Number of columns in the cursor result set. |
| row_count | decimal(10,0) | Number of rows affected by the last operation on the cursor. |
| last_operation | tinyint | Last operation performed on the cursor: 0 = No operations have been performed on the cursor. 1 = OPEN 2 = FETCH 3 = INSERT 4 = UPDATE 5 = DELETE 6 = CLOSE 7 = DEALLOCATE |
syscursortables
Contains the base tables referenced by a server cursor. This table
is stored in the master database. syscursortables table is
used by
sp_describe_cursor_tables system stored procedures to report the
base tables referenced by a server cursor.
| Column name | Data type | Description |
|---|---|---|
| cursor_handle | int | A unique value for the cursor within the scope of the server. |
| table owner | sysname, nullable | User ID of the table owner. |
| table_name | sysname, nullable | Name of the base table. |
| optimizer_hints | smallint | Bitmap consisting of one or more of: 1 = Row-level locking (ROWLOCK) 4 = Page-level locking (PAGELOCK) 8 = Table Lock (TABLOCK) 16 = Exclusive table lock (TABLOCKX) 32 = Update lock (UPDLOCK) 64 = No lock (NOLOCK) 128 = Fast first-row option (FASTFIRST) 4096 = Read repeatable semantic when used with declare cursor (HOLDLOCK) |
| lock_type | smallint | Scroll-lock type requested either explicitly or implicitly for each base table that underlies this cursor. The value can be: 0 = None 1 = Shared 3 = Update |
| server_name | sysname, nullable | Name of the linked server the table resides on. NULL if OPENQUERY or OPENROWSET are used. |
| objectid | int | Object ID of the table. 0 if OPENQUERY or OPENROWSET are used. |
| dbid | int | ID of the database the table resides in. 0 if OPENQUERY or OPENROWSET are used. |
| dbname | sysname, nullable | Name of the database the table resides in. NULL if OPENQUERY or OPENROWSET are used. |
sysfiles1
Contains one row for each file in a database. Each database contains
sysfiles1 system table.
| Column name | Data type | Description |
|---|---|---|
| status | int | For internal use only. |
| fileid | smallint | File identification number unique for each database. |
| name | nchar(128) | Logical name of the file. |
| filename | nchar(260) | Name of the physical device, including the full path of the file. |
sysfulltextnotify
Contains full-text catalog's notifications. sysfulltextnotify table
is
used by sp_fulltext_database, sp_fulltext_catalog,
sp_fulltext_table
and sp_fulltext_column system stored procedures.
Each database contains sysfulltextnotify system table.
| Column name | Data type | Description |
|---|---|---|
| tableid | int | Table ID. |
| rowinfo | smallint | For internal use only. |
| ftkey | varbinary(482) | Full-text key value. |
syslocks
Contains information about active locks. This table is provided for
backward compatibility only, and replaced by syslockinfo.
| Column name | Data type | Description |
|---|---|---|
| id | int | Table ID. |
| dbid | smallint | Database ID. |
| page | int | Page number. |
| type | smallint | Type of lock: 1 = Exclusive table lock 2 = Shared table lock 3 = Exclusive intent lock (will do page locking on indicated pages) 4 = Shared intent lock 5 = Exclusive page lock 6 = Shared page lock 7 = Update page lock (changes to exclusive lock if page is actually modified) 8 = Exclusive extent lock 9 = Update extent lock 11 = Next extent lock 12 = Previous extent lock Any of the above lock types can appear with 256 (0x100) added to them, indicating that the lock is blocking another user. 257 = Blocking exclusive table lock 265 = Blocking update extent lock |
| spid | smallint | ID of process that holds the lock. |
sysproperties
Contains extended properties that can be defined on various objects
in a database. The extended properties is a new SQL Server 2000
feature. These extended properties can be used to store a caption
for a table, view, or column, to store an input mask for a column,
to store the formatting rules for displaying the data in a column,
and so on. sysproperties table is used by sp_droptype,
sp_validatepropertyinputs, sp_addextendedproperty,
sp_updateextendedproperty, sp_dropextendedproperty
and sp_revokedbaccess system stored procedures to manage
extended properties, and by fn_listextendedproperty system
function to retrieve the value of an existing extended property.
Each database contains sysproperties system table.
| Column name | Data type | Description |
|---|---|---|
| id | int | Extended property id. |
| smallid | smallint | Data type id, or column id, or user id, or index id. |
| type | tinyint | Extended property type. |
| name | sysname | User-defined name of an extended property. |
| value | sql_variant, nullable | The value of an extended property. It can contains up to 7,500 bytes of data. |
sysxlogins
Contains each Windows NT account or group name and each SQL Server
login name. This table is stored in the master database.