We have a connection in Exasol (v7.0.18) to PostgreSQL (v14) created like this
create or replace connection POSTGRES_DB to
'jdbc:postgresql://hostname:5432/my_db?useCursorFetch=true&defaultFetchSize=2147483648'
user 'abc'
identified by <>;
I am running an export statement using this connection like this:
EXPORT MY_SCHEMA.TEST_TABLE
INTO JDBC AT POSTGRES_DB
TABLE pg_schema.test_table
truncate;
This works without any error.
The issue is that it runs only one insert statement in the PostgresSQL at a time. I am expecting multiple inserts running at a time in PostgresSQL.
This documentation page says Importing from Exasol databases is always parallelized. For Exasol, loading tables directly is significantly faster than using the STATEMENT option.
How can I make the export statement do parallel insert into PostgreSQL?
Related
I am trying to run the following query in pgAdmin:
CREATE DATABASE abc;
CREATE DATABASE xyz;
And I get the following error:
ERROR: current transaction is aborted, commands ignored until end of transaction block
SQL state: 25P02
I'm relatively new to postgres.
With SQL Server it's possible to create multiple databases in a single query with the "GO" statement in between if necessary.
I've tried to google this error, and most answers are to simply run each line separately.
That would work, but I'm curious why this doesn't work.
It may also be a setting in pgAdmin.
The "autocommit" is currently on. I've tried it off, and same result.
I'm using postgres 14.5 (in aws)
I am migrating Oracle database to Postgres Aurora. There is one Oracle PL/SQL block which checks if the database is in read write open mode. Below is the query like:
Select open_mode into v_open_mode from v$database;
if v_open_mode = 'READ WRITE' then
-- perform some steps.
I want to know if we have any equivalent query in Postgres. Or even if I can know the postgres node is WRITE mode.
I am also open to get anything which is native to Aurora which show if the node is reader or writer.
I am not sure what the Oracle thing does, but I assume the closest thing would be to check if Postgres is in recovery mode using pg_is_in_recovery()
So something like:
if not pg_is_in_recovery() then
-- do some steps
end if;
That is from "stock" Postgres, I don't know if Amazon Aurora does anything different or provides other functions.
I know the basic syntax of queries but otherwise I'm a beginner with SQL.
I have an SQL file (.sql) and I downloaded a couple programs (pgadmin and sql workbench).
I have no idea how to get from where I am now to actually writing queries and finding information. How do I set up so I can actually import my SQL file and start writing queries?
pgAdmin is the default GUI for PostgreSQL.
SQL Workbench is a free, DBMS-independent, cross-platform SQL query tool.
Either way, you need to connect to a database to actually run queries. The DBMS can either run on your local machine or you can connect to a remote server - where you need access privileges of course.
I need to create reports/summary tables on Redshift using SAS. My client data is on Amazon Redshift and he provided me all credentials to access the database. I have SAS 9.2 (32bit) and downloaded PostgresSQL 32bit driver to my system (as Redshift is based on PostgresSQL). I setup ODBC data source successfully and now I am connecting SAS using below command:
LIBNAME RdSft ODBC DSN='Redshift server' user='xxxxxxx' pw='xxxxxx';
data Rdsft.new_table;
set Rdsft.old_table(obs=10);
run;
I am able to connect and can see contents of tables on Redshift but not able to make any table there. Sometimes I could but its taking hours to create a table just with 10 observations. Someone suggested me to use DbVisulizer to do this task but I am comfortable with SAS only.
Please suggest.
If you have SAS/ACCESS try using the postgres engine for the library instead of going via ODBC eg:
libname RdSft postgres server="<server-address>" database=<db-name> port=5432 user='xxxxxxx' pw='xxxxxx';
Also, try adding conopts="UseServerSidePrepare=1" to the libname as suggested by this article: http://support.sas.com/kb/52/585.html
The simple fact of the matter, is that when you're connecting to Redshift via ODBC, even your simple data step query:
"data Rdsft.new_table;
set Rdsft.old_table(obs=10);
run;"
Is essentially translating to "select * from rdsft.old_table" before the obs subset is getting applied.
The SAS/ACCESS postgres solution is solid, you may also want to use proc sql, select only the columns you want, and subset as much as possible. Proc Sql will translate a bit easier into Redshift query language through an ODBC than the data step will.
SAS will hopefully be issuing a SAS/ACCESS for REDSHIFT option sometime soon! :)
Currently, I have an application that uses Firebird in embedded mode to connect to a relatively simple database stored as a file on my hard drive. I want to switch to using PostgreSQL to do the same thing (Yes, I know it's overkill). I know that PostgreSQL cannot operate in embedded mode and that is fine - I can leave the server process running and that's OK with me.
I'm trying to figure out a connection string that will achieve this, but have been unsuccessful. I've tried variations on the following:
jdbc:postgresql:C:\myDB.fdb
jdbc:postgresql://C:\myDB.fdb
jdbc:postgresql://localhost:[port]/C:\myDB.fdb
but nothing seems to work. PostgreSQL's directions don't include an example for this case. Is this even possible?
You can trick it. If you are running PostGRESQL on a UNIXlike system, then you should be able to create a RAMDISK and use that for the database storage. Here's a pretty good step by step guide for RAMdisks on Linux.
In general though, I would suggest using SQLITE for an SQL db in RAM type of application.
Postgres databases are not a single file. There will be one file for each table and each index in the data directory, inside a directory for the database. All files will be named with the object ID (OID) of db / table / index.
The JDBC urls point to the database name, not any specific file:
jdbc:postgresql:foodb (localhost is implied)
If by "disk that behaves like memory", you mean that the db only exists for the lifetime of your program, there's no reason why you can't create a db at program start and drop it at program exit. Note that this is just DDL to create the DB, not creating the data dir via the init-db program. You could connect to the default 'postgres' db, create your db then connect to it.
Firebird 2.1 onwards supports global temporary tables, which only exist for the duration of the database connection.
Syntax goes something like CREATE GLOBAL TEMPORARY TABLE ... ON COMMIT PRESERVE ROWS