Does Obiee support snowflake schema?
Snowflake schema is used in application layer of OBIEE.
What is a snowflake dimension?
The snowflake schema consists of one fact table that is connected to many dimension tables, which can be connected to other dimension tables through a many-to-one relationship. Tables in a snowflake schema are usually normalized to the third normal form. Each dimension table represents exactly one level in a hierarchy.
How do you attach snowflakes in Obiee?
You will need to provide the hostname, port, and credentials for your OBIEE server; these should be similar to the URL and credentials you use to login to the OBIEE UI. You should now create a new Database in the physical layer of your RPD. In OAS you can select Snowflake as the Database Type.
What is star schema Obiee?
Star Schema
These schemas are multidimensional structures which are used to create reports using BI reporting tools. Dimensions in Star schemas contain a set of attributes and Fact tables contain foreign keys for all dimensions and measurement values.
How do you turn a star schema into a snowflake?
You have to merge / aggregate / append your tables in Power Query to reduce the number of tables and get a star schema.
Is a snowflake a shape?
Shape. The shape of the snowflake is determined broadly by the temperature and humidity at which it is formed. Rarely, at a temperature of around −2 °C (28 °F), snowflakes can form in threefold symmetry — triangular snowflakes. Most snow particles are irregular in form, despite their common depiction as symmetrical.
Why do we use snowflake schema?
The purpose of a snowflake schema is to normalize the denormalized data in a star schema. This solves the write command slow-downs and other problems typically associated with “star schemas.” The snowflake schema is a “multi-dimensional” structure.
How do you connect snowflakes in Oracle?
Let us go through these steps to connect Oracle to Snowflake in detail.
- Step 1: Extract data from Oracle to CSV using SQL*Plus.
- Step 2: Data type conversion and formatting.
- Step 3: Stage Files to S3.
- Step 4: Copy staged files to Snowflake table.
What is difference between snowflake and star schema?
A star schema contains both dimension tables and fact tables in it. A snowflake schema contains all three- dimension tables, fact tables, and sub-dimension tables. It is a top-down model type. It is a bottom-up model type.
Which is better star schema or snowflake?
Which schema is better for performance? The Star schema is in a more de-normalized form and hence tends to be better for performance. Along the same lines the Star schema uses less foreign keys so the query execution time is limited. In almost all cases the data retrieval speed of a Star schema has the Snowflake beat.
What are the 6 types of snowflakes?
This system defines the seven principal snow crystal types as plates, stellar crystals, columns, needles, spatial dendrites, capped columns, and irregular forms. To these are added three additional types of frozen precipitation: graupel, ice pellets, and hail.
Can a snowflake have 8 sides?
So there is only a certain way they can fit together and what comes out is that they are always in a six-cornered shape, even at the tiniest molecular scale,” he says. Actually, water molecules occasionally form ice crystals with three or 12 sides — either half or double the usual number — but never five or eight.
Is snowflake OLAP or OLTP?
Snowflake is designed to be an OLAP database system. One of snowflake’s signature features is its separation of storage and processing: Storage is handled by Amazon S3. The data is stored in Amazon servers that are then accessed and used for analytics by processing nodes.
Can you join two 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.
Can we connect Snowflake to Oracle database?
There is no equivalent to Oracle database links in Snowflake. You would need an external process to move the data from Oracle to S3. Then you can configure a Snowpipe task to load from S3 into Snowflake.
What are pipes in Snowflake?
A pipe is a named, first-class Snowflake object that contains a COPY statement used by Snowpipe. The COPY statement identifies the source location of the data files (i.e., a stage) and a target table. All data types are supported, including semi-structured data types such as JSON and Avro.
Can we join 2 fact tables?
What are the different types of dimensions?
Top 9 Types of Dimension
- Conformed Dimensions. A dimension is considered a conformed dimension and is found in many places.
- Role Playing Dimensions.
- Shrunken Dimensions.
- Static Dimensions.
- Degenerate Dimensions.
- Rapidly Changing Dimensions.
- Junk Dimensions.
- Inferred Dimensions.
What snowflake is used for?
Snowflake enables data storage, processing, and analytic solutions that are faster, easier to use, and far more flexible than traditional offerings. The Snowflake data platform is not built on any existing database technology or “big data” software platforms such as Hadoop.
What is the shape of a snowflake?
Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) to one another. These ordered arrangements result in the basic symmetrical, hexagonal shape of the snowflake.
What is snowflake used for?
Snowflake can be used to fit to many use cases—data lakes with raw data, ODS with staged data, and data warehouse / data marts with presentable and modeled data. Data processing is simplified: Users can do data blending, analysis, and transformations against various types of data structures with a single language, SQL.
Is Snowflake an ETL tool?
Snowflake supports both transformation during (ETL) or after loading (ELT). Snowflake works with a wide range of data integration tools, including Informatica, Talend, Fivetran, Matillion and others.
Is Snowflake a relational DB?
Snowflake is fundamentally built to be a complete SQL database. It is a columnar-stored relational database and works well with Tableau, Excel and many other tools familiar to end users.
Is fact table is Normalised?
The fact table is always DE-NORMALIZED.
Can a table be both fact and dimension?
Additionally, any table in a dimensional database that has a composite key must be a fact table. This means that every table in a dimensional database that expresses a many-to-many relationship is a fact table. Therefore a dimension table can also be a fact table for a separate star schema.