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.

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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...

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