Retrieve unique values:

The "FetchSize" option suggests to the JDBC driver a number of rows to fetch on each visit to the database. Increasing this parameter reduces the amount of network traffic required to execute a query, at the cost of memory used:

Compute memory in use, including both kernel and Java layers:

Fetch a large result with a small fetch size:

Reset:

Fetch a large result with a large fetch size:

Retrieve data without converting it to Wolfram Language types:

For some variable-length column types the "MaxFieldSize" option can be used to limit the number of bytes returned for a field:

Create a table with a VARCHAR field:

Insert string data:

Select string contents, limiting byte length of results:

Limit the number of rows returned in a result:

Include column names as the first row of the results:

Specify columns to order by:

Supply a list of symbols for query results to be assigned to:

Create symbols automatically:

Supply a function to operate on column names and results. If column headings have not been requested, the first argument to the function will be Null: