Major Description
Postgres ODBC driver, retrieves all the rows from server for "select" request before it passes a single row to the calling client. This requires additional memory overhead for the client applications that dealing with very large resultset, which can lead to OOM issues. Postgres ODBC driver supports a couple properties
UseDeclareFetch = 1
Fetch=1000
using which, ODBC driver will form the queries using postgres "cursor" functionality, and only fetch number of rows that are defined with variable "Fetch". This will result in faster initial response time to the user (especially UI based apps) because the driver is not fetching all rows, it is only fetching the first batch. Also, minimal memory foot print as it can clear the results as they are delivered to the client application, especially with FORWARD only cursor. Teiid will only support for FORWARD ONLY cursor.