NULL DFLT ON/OFF

There are 2 interesting settings :

ANSI_NULL_DFLT_ON

ANSI_NULL_DFLT_OFF

These only affect the nullability of a new column , when nullability is not specified.

When SET ANSI_NULL_DFLT_OFF is ON – new columns are NOT NULL
When SET ANSI_NULL_DFLT_ON is ON – new columns allow null values if the nullability status of the column is not explicitly specified

Both SET ANSI_NULL_DFLT_OFF and SET ANSI_NULL_DFLT_ON cannot be set ON at the same time.
either ANSI_NULL_DFLT_OFF or SET ANSI_NULL_DFLT_ON can be set ON
or both can be set OFF

From BOL :

https://docs.microsoft.com/en-us/sql/t-sql/statements/set-ansi-null-dflt-off-transact-sql

https://docs.microsoft.com/en-us/sql/t-sql/statements/set-ansi-null-dflt-on-transact-sql

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IO block Size

I have read an interested blog post about the IO block Size.

Here it is .

Also, important information can be found here (please keep in mind it’s a sql server 2008 version).

The conclusions are:

• transaction log flushes – 512 Bytes UP TO 60KB
• data file IO
  • checkpoint – 8KB to 1MB
  • lazy writer -8KB to 1MB
  • reading – 8*8KB to 1MB
  • read ahead – 128KB to 512KB
  • bulk loads – 256KB
• Backup/restore – 1MB

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