Sample Schema for Event Series Joins Examples

If you don't plan to run the queries and just want to look at the examples, you can skip this topic and move straight to Writing Event Series Joins.

Schema of hTicks and aTicks Tables

The examples that follow use the following hTicks and aTicks tables schemas:

CREATE TABLE hTicks (
   stock VARCHAR(20), 
   time TIME, 
   price NUMERIC(8,2)
);
CREATE TABLE aTicks (
   stock VARCHAR(20), 
   time TIME, 
   price NUMERIC(8,2)
);

Although TIMESTAMP is more commonly used for the event series column, the examples in this topic use TIME to keep the output simple.

INSERT INTO hTicks VALUES ('HPQ', '12:00', 50.00);
INSERT INTO hTicks VALUES ('HPQ', '12:01', 51.00);
INSERT INTO hTicks VALUES ('HPQ', '12:05', 51.00);
INSERT INTO hTicks VALUES ('HPQ', '12:06', 52.00);
INSERT INTO aTicks VALUES ('ACME', '12:00', 340.00);
INSERT INTO aTicks VALUES ('ACME', '12:03', 340.10);
INSERT INTO aTicks VALUES ('ACME', '12:05', 340.20);
INSERT INTO aTicks VALUES ('ACME', '12:05', 333.80);
COMMIT;

Output of the two tables:

hTicks

 

aTicks
=> SELECT * FROM hTicks;

There are no entry records between 12:02–12:04:

 stock |   time   | price
-------+----------+-------
 HPQ   | 12:00:00 | 50.00
 HPQ   | 12:01:00 | 51.00
 HPQ   | 12:05:00 | 51.00
 HPQ   | 12:06:00 | 52.00
(4 rows)

 

=> SELECT * FROM aTicks;

There are no entry records at 12:01, 12:02 and at 12:04:

 stock |   time   | price
-------+----------+--------
 ACME  | 12:00:00 | 340.00
 ACME  | 12:03:00 | 340.10
 ACME  | 12:05:00 | 340.20
 ACME  | 12:05:00 | 333.80
(4 rows)

Example Query Showing Gaps

A full outer join shows the gaps in the timestamps:

=> SELECT * FROM hTicks h FULL OUTER JOIN aTicks a ON h.time = a.time;
 stock |   time   | price | stock |   time   | price
-------+----------+-------+-------+----------+--------
 HPQ   | 12:00:00 | 50.00 | ACME  | 12:00:00 | 340.00
 HPQ   | 12:01:00 | 51.00 |       |          |
 HPQ   | 12:05:00 | 51.00 | ACME  | 12:05:00 | 333.80
 HPQ   | 12:05:00 | 51.00 | ACME  | 12:05:00 | 340.20
 HPQ   | 12:06:00 | 52.00 |       |          |
       |          |       | ACME  | 12:03:00 | 340.10
(6 rows)

Schema of Bid and Asks Tables

The examples that follow use the following hTicks and aTicks tables.

CREATE TABLE bid(stock VARCHAR(20), time TIME, price NUMERIC(8,2));
CREATE TABLE ask(stock VARCHAR(20), time TIME, price NUMERIC(8,2));
INSERT INTO bid VALUES ('HPQ', '12:00', 100.10);
INSERT INTO bid VALUES ('HPQ', '12:01', 100.00);
INSERT INTO bid VALUES ('ACME', '12:00', 80.00);
INSERT INTO bid VALUES ('ACME', '12:03', 79.80);
INSERT INTO bid VALUES ('ACME', '12:05', 79.90);
INSERT INTO ask VALUES ('HPQ', '12:01', 101.00);
INSERT INTO ask VALUES ('ACME', '12:00', 80.00);
INSERT INTO ask VALUES ('ACME', '12:02', 75.00);
COMMIT;

Output of the two tables:

bid

 

ask
=> SELECT * FROM bid;

There are no entry records for stocks HPQ and ACME at 12:02 and at 12:04:

 stock |   time   | price
-------+----------+--------
 HPQ   | 12:00:00 | 100.10
 HPQ   | 12:01:00 | 100.00
 ACME  | 12:00:00 |  80.00
 ACME  | 12:03:00 |  79.80
 ACME  | 12:05:00 |  79.90
(5 rows)

 

=> SELECT * FROM ask;

There are no entry records for stock HPQ at 12:00 and none for ACMEat 12:01:

 stock |   time   | price
-------+----------+--------
 HPQ   | 12:01:00 | 101.00
 ACME  | 12:00:00 |  80.00
 ACME  | 12:02:00 |  75.00
(3 rows)

Example Query Showing Gaps

A full outer join shows the gaps in the timestamps:

=> SELECT * FROM bid b FULL OUTER JOIN ask a ON b.time = a.time;
 stock |   time   | price  | stock |   time   | price
-------+----------+--------+-------+----------+--------
 HPQ   | 12:00:00 | 100.10 | ACME  | 12:00:00 |  80.00
 HPQ   | 12:01:00 | 100.00 | HPQ   | 12:01:00 | 101.00
 ACME  | 12:00:00 |  80.00 | ACME  | 12:00:00 |  80.00
 ACME  | 12:03:00 |  79.80 |       |          |
 ACME  | 12:05:00 |  79.90 |       |          |
       |          |        | ACME  | 12:02:00 |  75.00
(6 rows)