I have the current query in athena.
SELECT col1,
col_2,
A.col_3
FROM
(SELECT col_1,
col_3
FROM table_1
JOIN col_3
WHERE col_1 IN
(SELECT DISTINCT col_1
FROM table_2
JOIN table_1
ON table_1.col_1 = table_2.col_1
)
) AS A
LEFT JOIN
(SELECT col_2,
col_3
FROM table_3
JOIN col_3
WHERE col_2 IN
(SELECT DISTINCT col_2
FROM table_2
JOIN table_4
ON table_2.col_1 = table_4.col_1
JOIN table_3
ON table_4.col_2 = table_3.col_2
)
) AS B
ON B.col_3 = A.col_3
Which works in SQLite.
But when I run it in AWS Athena I got the following error:
Queries of this type are not supported (Service: AmazonAthena; Status Code: 400; Error Code: InvalidRequestException; Request ID: some_id)
I assume that some part of this query is not supported by AWS Athena, but I am new to the Framework.
"Queries of this type are not supported" is Athena's generic way of saying that it doesn't understand your SQL, but that it's not a simple syntax error. You're using SQL that Athena does not support, in other words.
Run the innermost part of the query by itself, and if you don't get the error, add the SQL that wraps it, and so on until you find the fragment that causes the error. If you don't know how to fix it ask a new question focused on that.
Related
I try to run a query. there is a subquery on the join 'on' clause. Can i use subquery on the on clause. I got the error
Unsupported subquery with table in join predicate. Below is an example I made.
select '1' from `server.dataset.table` a
join `server.dataset.table` b
on a.AccountNumber= (select max(m.AccountNumber) from `server.dataset.table` m)
I sugested that in the join you need to relate the priamary key from table A to table B.
here is the example code code.
select '1' from `server.dataset.table` a
join `server.dataset.table` b
on a.primarykey=b.primarykey
where a.AccountNumber= (select max(m.AccountNumber) from `server.dataset.table` m)
I have an AWS database with multiple tables that I am trying to get the row counts for in a single query.
The ideal query output would be:
table_name row_count
table2_name row_count
etc...
So far I've been able to either get all the table names from the database or all the rowcounts of the tables (in random order), but not both in the same query.
This query returns a column of all the table names that exist in the database:
SELECT table_name FROM information_schema.tables WHERE table_schema = '<database_name>';
This query returns all the row counts for the tables:
SELECT COUNT(*) FROM table_name
UNION ALL
SELECT COUNT(*) FROM table2_name
UNION ALL
etc..for the rest of the tables
The issue with this query is that is displays the row counts in a random order that doesn't correspond with the order of the tables in the query, and so I don't know which row count goes with which table - hence why I need both the table names and row counts.
Simply add the names of the tables as literals in your queries:
SELECT 'table_name' AS table_name, COUNT(*) AS row_count FROM table_name
UNION ALL
SELECT 'table_name2' AS table_name, COUNT(*) AS row_count FROM table_name2
UNION ALL
…
The following query generates the UNION query to produce counts of all records.
The problem to solve is that (as of December 2022) INFORMATION_SCHEMA.TABLES incorrectly defines every table and view as a BASE TABLE so you will need some logic to eliminate the views.
In Data Warehousing it is common practise to record snapshots of the record counts of landing tables at frequent intervals. Any unexpected deviations from expected counts can be used for reporting/alerting
WITH Table_List AS (
SELECT table_schema,table_name, CONCAT('SELECT CURRENT_DATE AS run_date, ''',table_name, ''' AS table_name, COUNT(*) AS Records FROM "',table_schema,'"."', table_name, '"') AS BaseSQL
FROM INFORMATION_SCHEMA.TABLES
WHERE
table_schema = 'YOUR_DB_NAME' -- Change this
AND table_name LIKE 'YOUR TABLE PATTERN%' -- Change or remove this line
)
, Total_Records AS (
SELECT COUNT(*) AS Table_Count
FROM Table_List
)
SELECT
CASE WHEN ROW_NUMBER() OVER (ORDER BY table_name) = Table_Count
THEN BaseSQL
ELSE CONCAT(BaseSql, ' UNION ALL') END AS All_Table_Record_count_SQL
FROM Table_List CROSS JOIN Total_Records
ORDER BY table_name;
I got this statement, which works in Oracle:
update table a set
a.attribute =
(select
round(sum(r.attribute1),4)
from table2 p, table3 r
where 1 = 1
and some joins
)
where 1 = 1
and a.attribute3 > 10
;
Now I would like to do the same statement in Exasol DB. But I got error [Code: 0, SQL State: 0A000] Feature not supported: this kind of correlated subselect (Session: 1665921074538906818)
After some research, I found out you need to write the query in following syntax:
UPDATE table a
set a.attribute = r.attribute2
FROM table a, table2 p, table3 r
where 1 = 1
and some joins
and a.attribute3 > 10;
The problem is I can't take sum of r.attribute2. So I get unstable set of rows. Is there any way to do the first query in Exasol DB?
Thanks for help guys!
Following SQL UPDATE statement will work for cases if JOIN between table1 and table2 are 1-to-1 (or if there is a 1-to-1 relation between target table and resultset of JOINs)
In this case target table val column is updated otherwise an error is returned
UPDATE table1 AS a
SET a.val = table2.val
FROM table1, table2
WHERE table1.id = table2.id;
On the other hand, if the join is causing multiple returns for single table1 rows, then the unstable error raised.
If you want to sum the column values of the multiplying rows, maybe following approach can help
First sum all rows of table2 in bases of table1 and use this sub-select as a new temp table, then use this in UPDATE FROM statement
UPDATE table1 AS a
SET a.val = table2.val
FROM table1
INNER JOIN (
select id, sum(val) val from table2 group by id
) table2
ON table1.id = table2.id;
I tried to solve the issue using two tables
In your case probably you will use table2 and table3 in the subselect statement
I hope this is the answer you were looking for
I want to project forward the size of my Amazon Redshift tables because I'm planning to expand my Redshift cluster size.
I know how to query the table size for today (see query below) but how can I measure the growth of my table sizes over time without make an ETL job to make snapshot day-by-day table size?
-- Capture table sizes
select
trim(pgdb.datname) as Database,
trim(pgn.nspname) as Schema,
trim(a.name) as Table,
b.mbytes,
a.rows
from (
select db_id, id, name, sum(rows) as rows
from stv_tbl_perm a
group by db_id, id, name
) as a
join pg_class as pgc on pgc.oid = a.id
join pg_namespace as pgn on pgn.oid = pgc.relnamespace
join pg_database as pgdb on pgdb.oid = a.db_id
join (
select tbl, count(*) as mbytes
from stv_blocklist
group by tbl
) b on a.id = b.tbl
order by mbytes desc, a.db_id, a.name;
There is no historical table size information retained by Amazon Redshift. You would need to run a query on a regular basis, such as the one in your question.
You could wrap the query in an INSERT statement and run it on a weekly basis, inserting the results into a table. This way, you'll have historical table size information for each table each week that you can use to predict future growth.
It would be worth doing a VACUUM prior to such measurements, to remove deleted rows from storage.
Following metrics is available in cloudwatch
RedshiftManagedStorageTotalCapacity (m1)
PercentageDiskSpaceUsed (m2).
Create a cloudwatch math expression m1*m2/100 to get this data for the past 3 months.
I'm doing a count from table1 whose records/rows don't exist in table2
Here is the query:
select count(1) from table1
where not exists (select 1 from table2 where
table1.col1 = table2.col1
and table2.id=1)
I need to see the records that are missing in table2 , whose id in table2=1, and these records should be available in table1. The PK here is col1.
The query returns me 0. But if I do an excel sheet comparing by removing both the tables to excel. I can find 1591 records that are missing from table1 and are available in table2.
Your query is working fine.
You query finds records that EXISTS in table1 but not in table2
You have found with excel records that does NOT EXISTS in table1 and EXISTS in table2
If you'd like to find these records with SQL than your query should be:
select count(1) from table2
where table2.id=1 and table2.col1 not in (select col1 from table1)
or with not exists version of this query:
select count(1) from table2
where table2.id=1 and
not exists (select 1 from table1 where table1.col1=table2.col1)
I didn't test the queries.