Schema

A database transformation and migration project takes solid planning and testing. I’ve found that three common changes required when transforming a SQL Server database to YugabyteDB YSQL are related to syntax, performance, and stored procedures. These will get you started on your transformation project.

Syntax

Transforming a schema from MS SQL to YugabyteDB requires some minor syntax changes. This is true for any cross-database transformation. The YugabyteDB YSQL API utilizes PostgreSQL syntax.

I had to create a 10 million row table for testing recently, and put together a query to generate random data for it.

INSERT INTO my_table
(id,
mydatetime,
string1,
string2)

SELECT
(random() * 70 + 10)::int,
TIMESTAMP '2024-01-01 00:00:00.000000' + interval '1 millisecond' * (random() * 86400 * 1000 * 365),
(array['alligator','bear','cat','dog'])[(random() * 3 + 1)::int],
substr(md5(random()::text), 1, 10)

FROM generate_series(1, 10);

The id field is just a random integer in this example, but you’d probably use an identity column.

Math… the universal language. Timestamps, not so much.

The way we decide to denote date and time differs across both computer languages and human languages. The format also differs across implementations of SQL. For example, Oracle and Postgres allow very different formats to be entered in the timestamp data type.

Oracle allows a wide variety of punctuation in dates: hyphens, slashes, commas, periods, colons. Postgres supports a more limited list.