Support calculated predicates in pull queries

[vinothchandar]

While fixed predicates work

ksql> SELECT TIMESTAMPTOSTRING(WINDOWSTART, 'yyyy-MM-dd HH:mm:ss') AS WINDOW_START_TS, FULL_NAME,                                            >       RATINGS_COUNT
>  FROM RATINGS_PER_CUSTOMER_PER_MINUTE
>  WHERE ROWKEY='Rica Blaisdell'
>    AND WINDOWSTART > '2020-02-07T16:57:00.000';
+---------------------------------------------+---------------------------------------------+---------------------------------------------+
|WINDOW_START_TS                              |FULL_NAME                                    |RATINGS_COUNT                                |
+---------------------------------------------+---------------------------------------------+---------------------------------------------+
|2020-02-07 16:58:00                          |Rica Blaisdell                               |10                                           |
|2020-02-07 16:59:00                          |Rica Blaisdell                               |7                                            |
|2020-02-07 17:00:00                          |Rica Blaisdell                               |7                                            |
|2020-02-07 17:01:00                          |Rica Blaisdell                               |10                                           |
|2020-02-07 17:02:00                          |Rica Blaisdell                               |5                                            |
|2020-02-07 17:03:00                          |Rica Blaisdell                               |8                                            |
|2020-02-07 17:04:00                          |Rica Blaisdell                               |4                                            |
Query terminated
ksql> SELECT TIMESTAMPTOSTRING(WINDOWSTART, 'yyyy-MM-dd HH:mm:ss') AS WINDOW_START_TS, FULL_NAME, 
>                                                 RATINGS_COUNT
>  FROM RATINGS_PER_CUSTOMER_PER_MINUTE
>  WHERE ROWKEY='Rica Blaisdell'
>    AND WINDOWSTART > 1581008904345;
+---------------------------------------------+---------------------------------------------+---------------------------------------------+
|WINDOW_START_TS                              |FULL_NAME                                    |RATINGS_COUNT                                |
+---------------------------------------------+---------------------------------------------+---------------------------------------------+
|2020-02-07 16:35:00                          |Rica Blaisdell                               |4                                            |
|2020-02-07 16:36:00                          |Rica Blaisdell                               |7                                            |
|2020-02-07 16:37:00                          |Rica Blaisdell                               |8                                            |
|2020-02-07 16:38:00                          |Rica Blaisdell                               |6                                            |
|2020-02-07 16:39:00                          |Rica Blaisdell                               |9                                            |

Calculated predicate does n't

ksql> SELECT TIMESTAMPTOSTRING(WINDOWSTART, 'yyyy-MM-dd HH:mm:ss') AS WINDOW_START_TS, FULL_NAME,
>       RATINGS_COUNT
>  FROM RATINGS_PER_CUSTOMER_PER_MINUTE
>  WHERE ROWKEY='Rica Blaisdell'
>    AND WINDOWSTART > (UNIX_TIMESTAMP() - 86400000);
WINDOWSTART bounds must be BIGINT.
ksql> SELECT TIMESTAMPTOSTRING(WINDOWSTART, 'yyyy-MM-dd HH:mm:ss') AS WINDOW_START_TS, FULL_NAME,
>       RATINGS_COUNT
>  FROM RATINGS_PER_CUSTOMER_PER_MINUTE
>  WHERE ROWKEY='Rica Blaisdell'
>    AND WINDOWSTART > CAST((UNIX_TIMESTAMP() - 86400000) AS BIGINT);
WINDOWSTART bounds must be BIGINT.

Thanks @rmoff for reporting this!

[rmoff]

Confirmed as still not working in 0.11:

ksql> SELECT RECORD_CT
>  FROM MESSAGE_COUNT_BY_4HR
>  WHERE WINDOWSTART > (UNIX_TIMESTAMP()-(1000 * 60 * 60 * 4))
>    AND DUMMY_FIELD=1 ;
>
Window bounds must be an INT, BIGINT or STRING containing a datetime..  See https://cnfl.io/queries for more info.
Add EMIT CHANGES if you intended to issue a push query.
Pull queries require a WHERE clause that:
 - limits the query to a single key, e.g. `SELECT * FROM X WHERE <key-column>=Y;`.
 - (optionally) limits the time bounds of the windowed table.
         Bounds on `WINDOWSTART` and `WINDOWEND` are supported
         Supported operators are EQUAL, GREATER_THAN, GREATER_THAN_OR_EQUAL, LESS_THAN and LESS_THAN_OR_EQUAL

It would be really useful to support this - usecase being "give me the values from the last four hours"

[rmoff]

If we're not going to support this imminently then may I suggest an update to the error message, something like:

Only literal values are currently supported for pull query predicates.

[agavra]

This might have actually been fixed recently with the work we've done to support codegen in where clauses. cc @AlanConfluent can you confirm?

[AlanConfluent]

In theory we can support it now that we have codegen for the where clause. Unfortunately, we still make some assumptions about the structure of the clause, namely that if there's a comparison, one side of it is a column reference...

With table scans (or even an existing key reference), this assumption can be lifted. This requires a followup.

[rmoff]

Would be great if we can implement this suggestion in the meantime, it'll have users a lot of time :)

If we're not going to support this imminently then may I suggest an update to the error message, something like:

Only literal values are currently supported for pull query predicates.