Description
A context must be initialized before executing analytic functions. Use the td_set_context function to initialize a context
using an already established connection.
Note: If a context already exists, then this removes all nonpersistent work tables but does not
disconnect the connection in the existing context, unless it was created using td_create_context .
Usage
td_set_context(con, temp.database = NULL)
Arguments
con |
Required Argument |
temp.database |
Optional Argument
Default: NULL |
Value
Returns NULL invisibly
See Also
td_remove_context, td_create_context, td_get_context
Examples
# Establish an ODBC connection to Teradata Vantage using the dbConnect API. con <- DBI::dbConnect(odbc::odbc(), dsn = "TeradataDSN") # Example 1: Changing the temp.database of an existing context without removing # nonpersistent work tables. # Use td_set_context function to initialize a context with a given connection. td_set_context(con = con, temp.database = "database_for_transient_objects") # Use td_get_context function to get the current context information. context <- td_get_context() # Change the temp.database of an existing context. td_set_context(context$connection, temp.database = context$default.database) # Remove the current context. td_remove_context() # Example 2: Managing multiple connections with td_set_context. con1 <- DBI::dbConnect(odbc::odbc(), dsn = "TeradataDSN") con2 <- DBI::dbConnect(odbc::odbc(), dsn = "TeradataDSN") # Initialize the context with con1. td_set_context(con = con1, temp.database = "database_for_transient_objects") # Initialize the context with con2. td_set_context(con = con2) # Remove the current context. # Note: This performs garbage collection and disconnects current context connection i.e., con2. td_remove_context() # Explicit call to disconnect the connection con1. DBI::dbDisconnect(con1) # Example 3: Create a new ODBC context and switch its temporary database using # td_set_context. con <- td_create_context(dsn = "TeradataDSN") # Use td_get_context function to get the current context information. td_get_context() # Use td_set_context function to change temporary database. td_set_context(con, temp.database = "database_for_transient_objects") # Use td_get_context function to get the current context information. td_get_context() # Remove the current context. td_remove_context() # Example 4: Use dbConnect to connect to Advanced SQL Engine through Teradata SQL Driver # and set context using different temporary database. db <- DBI::dbConnect(tdplyr::NativeDriver(), <host_name>, <username>, <password>) # Use td_set_context function to set context using different temporary database. td_set_context(db, temp.database = "database_for_transient_objects") # Remove the current context. td_remove_context()