What are differences between schema on read vs schema on write

Hello friends, If you are talking about data, database , data-warehouse or big data nothing will complete without schema. Schema plays an important role in Data Platform. Today I am exploring about Schema on write and schema on read in respect of datawarehouse and data lake. Let see differences.

Schema on write

Structured Data,
RDBMS,
OLAP / Data-warehouse.
Heavy ETL (extract-transform-load) role in data movement.
Change in data-model is costly.
work well in range of Data Mart.
User have set of questions.
Business Analysis.
Collect Data - Apply Schema - Write Data - Analyze.

Schema on read

Structure & Un-structured Data.
RDBMS, NoSQ & Hadoop.
BigData / Data Lake.
ELT (extract-load-transform) & Low cost extraction.
Schema is just a structured file can be switched dynamically.
Ideal for large volume of data.
User is exploring data without pre-defined query.
Data science & Research.
Collect Data - Write Data - Apply Schema- Analyze.

Comments

mongoDB error : aborting after fassert() failure

What to do when facing errors on mongoDB “aborting after fassert() failure” I like errors, in mongoDB this is the first error I faced and luckily many times. This error i faced during restoring name-space on local and restarting db system. I am still searching the exact root cause of this issue but i am able to resolve the current problem through below steps. Remove all relevant namespace files from data-file route path.. Now repair mongo instance using mongod process. mongod --repair ////////// execute command from bin folder path Then start server using mongd process, if started server successfully then .. mongod ////////// execute command from bin folder path Restore last backups as normal process. Now check database by connecting mongo shell. Thanks for reading, Please comment your experience if you faced and also share knowledge if you have better steps to resolve... https://www.facebook.com/pages/Sql-DBAcoin/523110684456757

SQL71562: external references are not supported when creating a package from this platform

Last week I got this error from one of developer who was trying to deploy his project from Testing server to SQL Azure QA server. He was using “Deploy Database to SQL Azure” option from SSMS Tool-Task option. After connecting to SQL Azure portal when operation started to deployment below errors occurs. Validation of the schema model for data package failed. Error SQL71562: Error validating element xx.xxx.xx:function .dbo.xxx has an unresolved refrence to object xx.dbo.xxxx external refrences are not supported when creating a package from this platform . Reason: The reason of the this error was; some functions of project was dependent on master database and only single database was being deploy to SQL Azure. DACFx must block Export when object definitions (views, procedures, etc.) contain external references, as Azure SQL Database does not allow cross-database external references So, this error was coming. Solution : I suggested him to create those function to locally

How to add an article in Transactional Replication

If we have a set-up of Transactional Replication for Data Distribution running and wanting to add new object to replication on other server we can follow below process. To add an article In Transaction replication with PUSH Subscription

The Young DBA

Search This Blog