Utility Functions and C Language Reference > Virtual Table Server Functions (VTS) for C, C#, and Java > Virtual Table Server (VTS) Functions for Multiple Connections > Alphabetical Listing > vtc_ensure_index

vtc_ensure_index

Creates an index on a column.

C Language

VTCERR2 vtc_ensure_index ( PVCI2 pvci,  char *column_name, unsigned short *outRc );

C# Language

bool vts_multi.ensure_index ( int pvci,  string column_name);

Java Language

int Vtc.ensure_index (  long pvci,  string column_name, OutIntParameter outRc);
Global Functions

Arguments

Name Comments
pvci The server connection handle.
column_name The name of the column to index.
outRc The return status. 1 - Pass or 0 - Fail

vtc_ensure_index creates a column index. If a column is not indexed, the time required to execute a vtc_send_if_unique call increases with the number of rows. If the column is indexed, the time for 'send if unique' operations is constant. For large databases, we recommend that you index columns you want to perform 'send if unique' operations.

A column is locked while an index is being built on it. Any function calls that change the column are queued until the index build completes.

If the index exists, this function has no effect.

Return Values

C Language:   Returns zero on success or one of the Error Codes.

C# Language: Returns true on success.

Java Language:   Returns zero on success or one of the Error Codes.

Parameterization

All string input arguments can be passed using standard parameterization.

C Language Example

int      rc = 0;
unsigned short outrc;
PVCI2     pvci = 0;
....
rc = vtc_ensure_index(pvci, "C_credit", &outrc);
lr_log_message("ensure_index rc=%d\n", outrc);

C# Language Example

.Net Multiple Connection Example

Java Language Example

Java Multi-Connection Example