YugabyteDB lets you declare session variables and use them in a YSQL statement or stored procedure.
Example:
yugabyte=# SELECT * FROM test_schema.test_table;
c1 | c2 | c3
----+----+----
1 | A | Z
2 | B | Y
3 | C | X
(3 rows)
yugabyte=# SET myscope.c1 = 1;
SET
yugabyte=# SET myscope.c3 = 'Z';
SET
yugabyte=# SHOW myscope.c1;
myscope.c1
------------
1
(1 row)
yugabyte=# SHOW myscope.c3;
myscope.c3
------------
Z
(1 row)
yugabyte=# SELECT * FROM test_schema.test_table WHERE c1 = current_setting('myscope.c1')::INT AND c3 = current_setting('myscope.c3');
c1 | c2 | c3
----+----+----
1 | A | Z
(1 row)