I've a data as follows in the text file.
source_table_name | last_run_timestamp | freq_in_secs
------------------------------+---------------------+-----------------------
table1 | 08/19/2019 14:30:27 | 300
table2 | 08/19/2019 14:30:26 | 600
table3 | 08/19/2019 13:40:21 | 3660
I want to send an alert if last_run_timestamp + freq_in_secs + 1200 secs > current timestamp then shoot an alert.
I will have 100 rows like this in the file. I will have to read this file , do above calculation and then send alert using shell script.
Related
I have created a Informatica flow
where I need to read data from table that to only one column which contain empids.
But the column might contain duplicate need to write distinct values to file from below query
Query :
select distinct
emp_id
from
employee
where
empid not in
(
select distinct
custid
from
customer
);
I have added the above query in Source Qualifier
employee table contains : 5 million records and customer table contains : 20 billion records
My Informatica is still running not got completed - 6 hours over till now and nothing is written to file because of huge data in both tables
Following is my query plan
--------------------------------------------------------------------
Id | Operation | Name |
--------------------------------------------------------------------
0 | SELECT STATEMENT | |
1 | AX COORDINATOR | |
2 | AX SEND QC (RANDOM) | :AQ10002 |
3 | HASH UNIQUE | |
4 | AX RECEIVE | |
5 | AX SEND HASH | :AQ10001 |
6 | HASH UNIQUE | |
7 | HASH JOIN ANTI | |
8 | AX RECEIVE | |
9 | AX SEND PARTITION (KEY) | :AQ10000 |
10 | AX SELECTOR | |
11 | INDEX FAST FULL SCAN | PK_EMP_ID |
12 | AX PARTITION RANGE ALL | |
13 | INDEX FAST FULL SCAN | PK_CUST_ID |
--------------------------------------------------------------------
Sample table data :
employee
111
123
145
1345
111
123
145
678
....
customer
111
111
111
1345
111
145
145
145
145
145
145
....
Expected output :
123
678
Any solution is much appreciated !!!
It seems to me the SQL is the problem. If you dont have anything like sorter/aggregator, you dont have to worry about infa.
SQL seems to be having expensive operations. You can try below -
select emp_id
from employee
where not exists
(select 1 from customer where custid =emp_id)
This should be little faster because
you arent doing a subquery to get distinct from a 20billion customer table.
you dont need to use any distinct in first select because you are selecting from emp table where that emp id is unique. And not exist will make sure no duplicates coming out of first select.
You can also use left join +where but i think it will be expensive because of join-induced duplicates.
I would start with partitioning the customer table by hash or range(customer_id) or insert_date, this would speed up your inline select substantially.
Also try this:
select emp_id from employee
minus
select emp_id from employee e, customer c
where e.emp_id=c.custid;
We have code and products across different domains. We are tracking different timestamps at which the products transmit data. This how my data looks:
| timestamp_s | Product | Code | _c3 |
| 2017-01-01 01:18:04.40736 | A | 119 | 1 |
| 2017-01-01 01:18:05.20419 | A | 119 | 1 |
| 2017-01-01 01:18:11.21268 | A | 119 | 1 |
| 2017-01-01 10:48:22.52147 | A | 119 | 1 |
I want to find the total timestamps recorded for a product and code across different timestamps. Meaning like in the above case, the output count of timestamps for 2017-01-01 should be 4 for a unique product A and code 119 combination.
Basically, I want to see the total number of timestamp records for each day (meaning, the total count of all timestamp record(s) for 2017-01-01 as in the above case).
Use simple groupby+count distinct:
select count(distinct timestamp_s) ts_count, Product, Code
from table_name
group by Product, Code
Or if you need to have additional column with count on the same grain (without group by) use analytic function:
select timestamp_s, count(distinct timestamp_s) over(partition by Product, Code) ts_count, Product, Code
from table_name
I'm traying to make the below transformation in presto:
From:
id | valid_from | valid_unitl | value
12 | 2021/02/17 | 2021/05/17 | 150
To:
id | date | value
12 | 2021/02/17 | 150
12 | 2021/03/17 | 150
12 | 2021/04/17 | 150
12 | 2021/05/17 | 150
Is it possible?
Thanks,
You can use the sequence function to generate an array between valid_from and valid_until with the desired step and then unnest it:
select id, format_datetime(date,'yyyy/MM/dd') as date, value
from my_table
cross join unnest(sequence(parse_datetime(valid_from,'yyyy/MM/dd'),
parse_datetime(valid_until,'yyyy/MM/dd'),
interval '1' month)) t(date)
See the docs for the sequence function: https://prestodb.io/docs/current/functions/array.html
I encountered a very weird result while trying to filter my data using RAND() function.
Suppose i have a table filled with some data:
CREATE TABLE `status_log` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`rank` int(11) DEFAULT 50,
)
Then i do the following simple select:
select id,rank as rank,(rand()*100) as thres
from status_log
where rank = 50
and have a clear and expected output:
<...skip...>
| 6575476 | 50 | 34.51090244065123 |
| 6575511 | 50 | 67.84258230388404 |
| 6575589 | 50 | 35.68020727083106 |
| 6575644 | 50 | 74.87329251586766 |
| 6575723 | 50 | 67.32584384020961 |
| 6575771 | 50 | 12.009344726809621 |
| 6575863 | 50 | 58.06919518678374 |
+---------+------+-----------------------+
66169 rows in set (2.502 sec).
So, i generate some random data from 0 to 100 and join each result to the table, around 66000 results in total.
Then i want only a (random) part of the data to be shown. It doesn't have any purpose for production, by the way, it's just some artificial test, so let's not discuss it.
select *
from (
select id,rank as rank,(rand()*100) as thres
from status_log
where rank = 50) t
where thres>rank
order by thres;
After that i get the following:
<...skip...>
| 4396732 | 50 | 99.97966075314177 |
| 4001782 | 50 | 99.98002871869134 |
| 1788580 | 50 | 99.98064143581375 |
| 5300286 | 50 | 99.98275954274717 |
| 146401 | 50 | 99.98552389441573 |
| 4744748 | 50 | 99.98644758014609 |
+---------+------+--------------------+
16449 rows in set (2.188 sec)
It's obvious that for the mean of 50 the expected number of results should be around 33000 out of total 66000. So it seems that the distribution of rand() is biased, correct?
Let's then change > to <:
select *
from (
select id,rank as rank,(rand()*100) as thres
from status_log
where rank = 50) t
where thres<rank
order by thres;
<...skip...>
| 4653786 | 50 | 49.98035016467827 |
| 6041489 | 50 | 49.980370281245904 |
| 5064204 | 50 | 49.989308742796354 |
| 1699741 | 50 | 49.991373205549436 |
| 3234039 | 50 | 49.99390454030959 |
| 806791 | 50 | 49.99575274996064 |
| 3713581 | 50 | 49.99814410693771 |
+---------+------+----------------------+
16562 rows in set (2.373 sec)
Again 16000! So not the half but the quarter of all results is shown!
It seems that the output of rand() inside the brackets is somehow influenced with the expression outside them. How is this possible?
I can also union it:
select * from (select id,rank as rank,(rand()*100) as thres from status_log where rank = 50) t where thres<50
UNION ALL
select * from (select id,rank as rank,(rand()*100) as thres from status_log where rank = 50) t where thres>=50;
The expected number of results has to be somewhere around 66000, but it returns only 33000 or so.
I observe this behavior only when rand() is non-deterministic and is generated dynamically each time. If i do ...select id,rank as rank,(rand(id)*100)... (i.e. make the output of rand() dependent of id), i start getting the expected number of results (33000-ish). The same happens if i precalculate and fill a temporary field in the table.
I also tried making the filtering with rank=30, and the results were ~6000 and ~32000 for < and > respectively.
Version 10.5.8-MariaDB-3, InnoDB
Using a single query with HAVING instead of a subquery with WHERE in the main query seems to work around it.
select id,rank as rank,(rand()*100) as thres
from status_log
where rank = 50
having thres > rank
order by thres
This appears to be this bug:
RAND() evaluated and filtered twice with subquery
I have a query like this:
SELECT * FROM TEST1 LEFT OUTER JOIN TEST2 on TEST1.ID=TEST2.ID
UNION ALL
SELECT * FROM TEST3 LEFT OUTER JOIN TEST4 on TEST3.ID=TEST4.ID;
The behavior I see here is, it first join TEST1 and TEST2 tables (billions of rows) and then stores the output in temp tablespace. Then it joins TEST3 and TEST4 and then saves the output in same temp table. And finally select the records from there to display the result.
This behavior I see in both Redshift and Oracle. I was just wondering why it stores the result in temporary segments after getting result from first SELECT. It's time taking as well as eats up the temp space. Can not it just starts displaying the result after 1st SELECT is finishes and then goes for 2nd one (instead of storing).
This answer is somewhat speculative, because I don't have an Oracle doc reference. By inspection, we can imagine instead that you wanted to run the following query:
SELECT * FROM TEST1 JOIN TEST2
UNION ALL
SELECT * FROM TEST3 JOIN TEST4
ORDER BY some_col;
It should be clear that to apply any set operation like ORDER BY, all the records returned from the union query would need to be in one logical place. A temp table would seem to work.
That you are not using ORDER BY appears to not affect the workflow which Oracle is using.
I can also add another reason why Oracle is insisting on using a temp table here. Suppose it would be possible to write both halves of the union directly to the buffer. But what would happen if, at a later date, the size of the total union query suddenly exceeded what the buffer can hold? The answer is that your database would crash. So, using a temp table is a safe bet which should generally always work.
How do you observe this behaviour? By any chance don't you perform INSERT or CREATE TABLE? That would explain your observation, because at the end, all rows are required.
Also if your client has set an option fetch all rows this could be observed.
But in normal case, where the client is interested in few first rows Oracle returns quickly the first available (array size) rows from the first join ignoring the second one.
You may perform this little Gedankenexperiment:
create table test1 as
select rownum id,
lpad('x',1023,'X') pad
from dual connect by level <= 1000000;
Create analog the table 2 to 4.
Now run your query (adapted to valid syntax)
SELECT * FROM TEST1 CROSS JOIN TEST2
UNION ALL
SELECT * FROM TEST3 CROSS JOIN TEST4;
This returns for my the first page in SQL Developer in ca 30 seconds, which somehow disproves your claim.
Simple calculate the required TEMP space for two 10**6 * 10**6 cartesian join with row lenth 1K - this is far above my TEMP configuration.
The one possible way to observe what is Oracle actualy doing is to run the query with the /*+ gather_plan_statistics */ hint.
Than get the SQL_ID of the statement and check the actual rows A-Rowsin the plan
select * from table(dbms_xplan.display_cursor('a9y62gxagups6',null,'ALLSTATS LAST'));
SQL_ID a9y62gxagups6, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM TEST1 CROSS JOIN TEST2
UNION ALL SELECT * FROM TEST3 CROSS JOIN TEST4
Plan hash value: 1763392637
--------------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Starts | E-Rows | A-Rows | A-Time | Buffers | Reads | Writes | OMem | 1Mem | Used-Mem |
--------------------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | | 50 |00:00:28.52 | 166K| 166K| 142K| | | |
| 1 | UNION-ALL | | 1 | | 50 |00:00:28.52 | 166K| 166K| 142K| | | |
| 2 | MERGE JOIN CARTESIAN| | 1 | 1000G| 50 |00:00:28.52 | 166K| 166K| 142K| | | |
| 3 | TABLE ACCESS FULL | TEST1 | 1 | 1000K| 1 |00:00:00.02 | 4 | 28 | 0 | | | |
| 4 | BUFFER SORT | | 1 | 1000K| 50 |00:00:28.49 | 166K| 166K| 142K| 1255M| 11M| 97M (0)|
| 5 | TABLE ACCESS FULL | TEST2 | 1 | 1000K| 1000K|00:00:03.66 | 166K| 166K| 0 | | | |
| 6 | MERGE JOIN CARTESIAN| | 0 | 1000G| 0 |00:00:00.01 | 0 | 0 | 0 | | | |
| 7 | TABLE ACCESS FULL | TEST3 | 0 | 1000K| 0 |00:00:00.01 | 0 | 0 | 0 | | | |
| 8 | BUFFER SORT | | 0 | 1000K| 0 |00:00:00.01 | 0 | 0 | 0 | 1103M| 10M| |
| 9 | TABLE ACCESS FULL | TEST4 | 0 | 1000K| 0 |00:00:00.01 | 0 | 0 | 0 | | | |
--------------------------------------------------------------------------------------------------------------------------------------
You see, that Oracle
1) full scanned the table2 (row 5)
2) get one row from table1 (row 3)
3) to return to frist 50 rows (row 0)
4) tables 3 and 4 are untached (rows 7 and 9)
You may simple adapt the example to you inner join to see similar results.