I'm trying to use flyway on a DB2 / zOS instance and I get an error when trying to migrate or baseline.
java.lang.UnsupportedOperationException: Create Schema - is not supported in db2 on zOS
at org.flywaydb.core.internal.dbsupport.db2zos.DB2zosSchema.doCreate(DB2zosSchema.java:62)
This limitations is documented on Flyway website but how to workaround it?
Actually the DB is in place and schema is yet created with the same name gave into config as first and only schema. ("flyway.schemas=MYSCHEMA")
Migration should only execute a bunch of insert.
Baseline should only create flyway metadata table (flyway.table)
What am I missing?
Related
I tried to build an Offer-Ready Docker container on Azure Cloud. Although I created a new (blank) table in PostgreSQL, I got this strange error message.
javax.servlet.ServletException: org.eclipse.jetty.servlet.ServletHolder$1: org.flywaydb.core.api.FlywayException: Found non-empty schema(s) "public" without schema history table! Use baseline() or set baselineOnMigrate to true to initialize the schema history table.
I double-checked the database, there is no table in schema "public". I didn't have that problem on AWS. Has anybody an idea what is different on Azure?
I had the same experience once.
The PostgreSQL database on Azure seemed empty (\dt returned no results),
But Flyway claimed the database was not empty (and therefore would not apply the migration scripts, for fear of interfering with whatever was already there).
Here is what I did was:
Create a new schema within the database e.g. myschema
Delete the default schema called public
Add the parameter currentSchema=myschema to the JDBC URL
And then it worked. I never got to find out what the root cause of this problem was.
EDIT: This link might provide more information on what objects are in the "public" schema by default on Azure PostgreSQL: https://community.atlassian.com/t5/Jira-questions/Re-quot-database-that-is-not-empty-quot-when-trying-to-use-azure/qaq-p/1308795/comment-id/410329#M410329
I have created a Postgresql database A using liquibase changesets. Now, I'm creating an application that allows creating a new database B and copies the schema from database A in real-time including the liquibase changesets as the database can still be updated later. Note that at the time of the copied schema in database A could already be updated, making the base changesets outdated.
My main question would be:
How to copy PostgreSQL schema x from database a (dynamically generated at run-time) to b using liquibase? Database b could be on another server.
If it's not possible with liquibase, what other tools or approaches would make this possible?
--
Let me add more context:
We initialize a new database a schema using liquibase changeset.
We can add a new table and field to the database an at run-time. Or during the time when the application is running. For example, we add a new table people to the schema of database a, which is not originally in the changeset. This is done using liquibase classes too. So changeset is added to databasechangelog table.
Now, we create a new database b.
We want to import the schema of the database a to b, with people table.
I hope that is clear.
Thanks.
All schema changes must be run through your schema migration tool
The point of using a database schema migration tool such as Liquibase or Flyway is to have a “single source of truth” regarding the structure of your database tables. Your set of Liquibase changesets (or Flyway scripts) is supposed to be that single source of truth for your database.
If you are altering the structure of you database at runtime, such as adding a table named people, outside the scope of your migration tool, well, then you have violated the rules of the game. You will have defeated the purpose of using a schema migration tool. The intention of using a schema migration tool is that you make all schema changes through that tool.
If you need to add a table while running in production, you should be dropping the physical file for the Liquibase changeset (or Flyway script) into the file system of your database server environment, and then invoking Liquibase (or Flyway) to run a migration.
Perhaps you have been misunderstanding the sequence of events:
If you have built a database on server "A", that means you installed Postgres, created an empty database, then installed the collection of Liquibase changesets you have carefully built, then ran a Liquibase migration operation on that server.
When you go to create a database on server "B", you should be following the same steps: Install Postgres, create an empty database, installing the very same collection of Liquibase changesets, and then running a Liquibase migration operation.
Alternatively, if making a copy of server "A" to create server "B", that copy should include the exact same Liquibase changesets. So at the end of your copy process, the two databases+changesets are identical.
Here's how I solved this problem of mine using the Liquibase Java library:
1.) Export the changelog from the source database into a temporary file (XML).
Liquibase liquibase = new Liquibase(liquibaseOutFile.getAbsolutePath(), new FileSystemResourceAccessor(), sourceDatabase);
liquibase.generateChangeLog(catalogAndSchema, changeLogWriter, new PrintStream(liquibaseOutFile.getAbsolutePath()), null);
2.) Execute the temporary file to the new data source.
Liquibase targetLiquibase = new Liquibase(liquibaseOutFile.getAbsolutePath(), new FileSystemResourceAccessor(), targetDatabase);
Contexts context = new Contexts();
targetLiquibase.update(context);
Here's the complete code: https://czetsuya-tech.blogspot.com/2019/12/generate-postgresql-schema-using-java.html
I'm trying to setup a simple replication from MySQL to Postgres. Identical schemas. After following the steps in the Demo Tutorial with a slight change (using MySQL and Postgres drivers) I am still unable to get the replication working.
A few changes were needed based on complaints after running bin/sym
SET GLOBAL show_compatibility_56 = ON needed to be set in the MySQL DB
For Postgres I needed to use protocolVersion=3 instead of 2 which was set in the example.
The weird thing is that SymmetricDS is able to create the sym_* tables, but complains about not being able to read them. I have verified that the tables do not exist before bin/sym is run, but do exist after. Here is an excerpt from the log
// Successful creation of table
[store-001] - PostgreSqlSymmetricDialect - DDL applied: CREATE TABLE "sym_notification"(
"notification_id" VARCHAR(128) NOT NULL,
...
PRIMARY KEY ("notification_id")
)
...
// Unable to read from created table
[store-001] - PostgreSqlDdlReader - Failed to read table: sym_notification
[store-001] - PostgreSqlDdlReader - Failed to read table: sym_notification
[store-001] - AbstractDatabaseWriter - Did not find the sym_notification table in the target database
[store-001] - PostgreSqlDdlReader - Failed to read table: sym_monitor
[store-001] - PostgreSqlDdlReader - Failed to read table: sym_monitor
[store-001] - AbstractDatabaseWriter - Did not find the sym_monitor table in the target database
The same error apply for all the sym_* tables.
The databases are running in Docker, but since SymmetricDS is not complaining about being unable to connect, and is able to create the tables, I assume it is not related to Docker.
The database in the Postgres DB is created by the same user as specified in engines/store-001.properties. Could this still have something to do with roles and access privileges?
If you upgrade to the latest JDBC driver from Postgres it will work.
Replace the existing Postgres driver from the lib directory from the latest from here: https://jdbc.postgresql.org/download.html
Try to connect to the postgres database with the same username/password used by symmetric-ds from some DB navigator, for example Jetbrain's Datagrip and then try inserting, updating, selecting something from sym_* tables. Assign access rights to the user if necessary.
When using Postgres 9.6.1 (current latest release) the following error is logged on the server when running bin/sym
ERROR: column am.amcanorder does not exist at character 427
The problem was resolved by using Postgres 9.5.5 instead thanks to Nick Barnes pointing this out in a comment.
I have got a sql file where is configured a database in PostgreSQL technology. I created a database from sql file but from code it is hard to understand action/connecting between the tables. Is it some tool which show all the connections between tables for PostgreSQL?
pgDesigner
Data Architect
Datastudio
DbDesigner fork
DbSchema
dbwrench
DeZign for Database
Please take a look to this list of tools.
I have the following code to generate the schema for a database in Nhibernate
new SchemaExport(configuration).Execute(true, true, false);
but when run against a PostgreSQL database, I end up getting the following error
[NpgsqlException (0x80004005): FATAL: 3D000: database "dbname" does not exist]
If I however create the database manually, the schema is exported without errors. An so the question: Why is Nhibernate SchemaExport unable to create a PostgreSQL database and yet this works against other databases like SQLite, MsSqlCe and MsSql Server.
I have searched for online literature but have been unable to locate any highlighting on this issue.
I am using Nhibernate 3.3.1 with PostgreSQL 9.2.
You must create the database before you can create the tables and other objects within the database.
Do this with a CREATE DATABASE statement on a PostgreSQL connection - either in your app, or via psql or PgAdmin-III.
PostgreSQL doesn't support creating databases on demand / first access. Perhaps that's what your tool is expecting?
If you think the DB does exist and you can see it in other tools, maybe you're not connecting to the same database server? Check the server address and port.