SQL also supports the use of aggregate expressions (or functions) that allow you to summarize information about a group of rows of data. SELECT AGG_FUNC(column_or_expression) AS aggregate_description, … FROM mytable…
A JOIN clause is used to query and access data from multiple tables by using logical relationships between them. Join syntax SELECT column, another_column, … FROM mytable INNER/LEFT/RIGHT/FULL JOIN another_table…
To delete duplicates from a table, you’ll need to identify the duplicate rows first and then delete them using SQL. The approach varies slightly depending on whether you’re working with…
Identify duplicates criteria The first step is to define your criteria for a duplicate row. Do you need a combination of two columns to be unique together, or are you…
SQL LIMIT and OFFSET LIMIT: Limits the number of rows returned by a query OFFSET: Specifies how many rows to skip before returning the results Here’s an example of using…
Pyspak complete tutorial from scratch Shuffle: when data persists and is shared with other executors.whenever shuffle happens job is get divided into stages Driver Executor in the following diagram, the…
Table of Contents Toggle Limitations can you create a partition without clustering? Limitations maximum 8000 partitions possible on a single table and upto 4 columns can be used for clustering…
Table of Contents Toggle what is time travel in bigquery? Big query time travel – query for extracting data for last 24 hour. what is time travel in bigquery? Using…
HAVING Clause is used to filter the records from the groups based on the given condition. HAVING clause alwaysed used after
Federated queries are used to query the data on external sources like Cloud Storage, BigTable, CloudSql, Spreadsheet in google Drive. Federated queries or have queries that access data that isn’t…
Vishal Jadhav