Function createPartitions

src/bin/pgbench/pgbench.c:3987–4051

* Create "pgbench_accounts" partitions if needed. * * This is the larger table of pgbench default tpc-b like schema * with a known size, so we choose to partition it. */

 * with a known size, so we choose to partition it.
 */
static void
createPartitions(PGconn *con)
{
	PQExpBufferData query;

	/* we must have to create some partitions */
	Assert(partitions > 0);

	fprintf(stderr, "creating %d partitions...\n", partitions);

	initPQExpBuffer(&query);

	for (int p = 1; p <= partitions; p++)
	{
		if (partition_method == PART_RANGE)
		{
			int64		part_size = (naccounts * (int64) scale + partitions - 1) / partitions;

			printfPQExpBuffer(&query,
							  "create%s table pgbench_accounts_%d\n"
							  "  partition of pgbench_accounts\n"
							  "  for values from (",
							  unlogged_tables ? " unlogged" : "", p);

			/*
			 * For RANGE, we use open-ended partitions at the beginning and
			 * end to allow any valid value for the primary key.  Although the
			 * actual minimum and maximum values can be derived from the
			 * scale, it is more generic and the performance is better.
			 */
			if (p == 1)
				appendPQExpBufferStr(&query, "minvalue");
			else
				appendPQExpBuffer(&query, INT64_FORMAT, (p - 1) * part_size + 1);

			appendPQExpBufferStr(&query, ") to (");

			if (p < partitions)
				appendPQExpBuffer(&query, INT64_FORMAT, p * part_size + 1);
			else
				appendPQExpBufferStr(&query, "maxvalue");

			appendPQExpBufferChar(&query, ')');
		}
		else if (partition_method == PART_HASH)
			printfPQExpBuffer(&query,
							  "create%s table pgbench_accounts_%d\n"
							  "  partition of pgbench_accounts\n"
							  "  for values with (modulus %d, remainder %d)",
							  unlogged_tables ? " unlogged" : "", p,
							  partitions, p - 1);
		else					/* cannot get there */
			Assert(0);

		/*
		 * Per ddlinfo in initCreateTables, fillfactor is needed on table
		 * pgbench_accounts.
		 */