public int getMatchingRecordCount(Field field, int columnIndex) throws IOException {
		synchronized (db) {
			IndexTable indexTable = secondaryIndexes.get(columnIndex);
			if (indexTable == null) {
				throw new IOException("Index required (" + getName() + "," + columnIndex + ")");
			}
			return indexTable.getKeyCount(field);
		}
	}
Get the number of records which contain the
specified field value in the specified record column.  The table must
have been created with a secondary index on the specified column index.
@param field the field value
@param columnIndex the record schema column which should be searched.
@return number of records which match the specified field value.
@throws IOException if a secondary index does not exist for the specified
column, or the wrong field type was specified, or an I/O error occurs.
Ghidra/Framework/DB/src/main/java/db/Table.java