What is multi pass SQL?

What is multi pass SQL?

Multi-pass SQL refers to the creation of multiple queries against a database to accomplish complex comparisons to answer sophisticated questions. Mixing the grains of measurement in the same query such as year-to-date and month-to-date.

What is SQL passthrough?

Pass-through SQL lets you use native SQL without any of the restrictions that the data source imposes on subqueries. This is because pass-through SQL query subjects are not processed as subqueries. Instead, the SQL for each query subject is sent directly to the data source where the query results are generated.

Can we join 2 fact tables?

The answer for both is “Yes, you can”, but then also “No, you shouldn’t”. Joining fact tables is a big no-no for four main reasons: 1. Fact tables tend to have several keys (FK), and each join scenario will require the use of different keys.

How do you join multiple fact tables?

There are 2 approaches to do this:

1. Create a “fact table bridge” table. The bridge table contains the fact key columns of each fact table, plus any filtering columns required.
2. Create a new fact table containing all the required measures at the combined grain.

How do you create a passthrough query?

Create a pass-through query

1. Connect to a server database.
2. Select Create > Query Design.
3. If necessary, close the Add Tables dialog box (Show Table in Access 2013.
4. Select Design >Pass-Through.
5. If the query property sheet does not appear, press F4 to display it.

Which is better snowflake schema or star schema?

The Star schema is easier for readability because its query structure is not as complex, on the other hand the Snowflake has a complex query structure and is tougher for readability and implementing changes. The Star schema on the other hand uses less joins and tends to have more data redundancy.

Is time a fact or dimension?

The time dimension is a unique and powerful dimension in every data mart and enterprise data warehouse. Although one of the tenets of dimensional modeling is that all dimensions are created equal, the truth is that the time dimension is very special and must be treated differently from the other dimensions.

Can you have 2 fact tables?

You know you need a multi- fact table model when…you have a similar but different type of facts. These tables contain similar facts, they both deal with money, but the tracking is different. One table contains columns that are only relevant to budgeting while the other expenses.

How do I join a fact and dimension table in SQL Server?

To create a connection, a line with arrows, between a fact table and a dimension table in the SSMS diagram panel, we specify a primary key for each dimension entity, and assign foreign keys in the fact entities. User-defined data types are used to describe these keys.

What are the advantages of ODBC?

Some of the advantages of ODBC are: ODBC provides a consistent interface regardless of the kind of database server used. You can have more than one concurrent connection. Applications do not have to be bound to each database on which they will run.

What is ODBC in SQL Server?

Microsoft Open Database Connectivity (ODBC) is an application programming interface (API) designed to access data from a different of database management systems (DBMS). The diagram below explains the flow of connecting to a SQL Server database using the MSDASQL provider and a SQL Server ODBC driver.