SQL Joins (anti, self, natural, lnner, left, right, full join)
Vishal Jadhav A JOIN clause is used to query and access data from multiple tables by using logical relationships between them. Join syntax The INNER JOIN is a process that matches rows…
Data Engineering
How to delete duplicates from a 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…
How to find duplicates in a table
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…
Pyspark Zero to Expert Tutorial
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…
partition and clustering – BigQuery
Limitations maximum 8000 partitions possible on a single table and upto 4 columns can be used for clustering Partition can be done on Date, DATETIME, TIMESTAMP OR INTERGER RANGE COLUMN.…
Time travel – BigQuery
what is time travel in bigquery? Using big-query’s time travel concept we can access any modified(updated or delete) data. we can access this data till last 7 days. This concept…
Difference Between WHERE and HAVING Clause in sql
HAVING Clause is used to filter the records from the groups based on the given condition. HAVING clause alwaysed used after
What is a federated query in BigQuery?
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…
BigTable – Tall tables vs narro Tables
Bigtable is a NoSQL database service provided by Google Cloud Platform (GCP), designed to handle massive-scale, high-throughput workloads. While it’s commonly associated with storing and processing large amounts of data,…
Ultimate Guide to BigQuery Slots: Boosting Performance and Managing Costs Efficiently
BigQuery slots are a fundamental aspect of Google Cloud’s BigQuery service, which is a fully managed, serverless, highly scalable, and cost-effective multi-cloud data warehouse. Slots represent the computational power required…