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To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more information on this in the MySQL Documentation.

I wrote earlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is preventing needless deadlocks on pages.

I hope this helps !!!

To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more information on this in the MySQL Documentation.

I wrote earlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is preventing needless deadlocks on pages.

I hope this helps !!!

To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more information on this in the MySQL Documentation.

I wrote earlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is too prevent needless deadlocks on pages.

I hope this helps !!!

To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more information on this in the MySQL Documentation.

I wrote earlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is preventing needless deadlocks on pages.

I hope this helps !!!

To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more on this in the MySQL Documentation.

I wrote easrlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is too prevent needless deadlocks on pages.

I hope this helps !!!

To some extent, yes.

When it comes to InnoDB, you can choose what rows can get locked. It is not so much a particular setting for the DB Connection. It is a specific query you have to call before doing UPDATEs.

• SELECT ... FOR UPDATE
• SELECT ... LOCK IN SHARE MODE

This can initiate exclusive or shared row locks based on the result set of those SELECTs.

You can find more information on this in the MySQL Documentation.

I wrote earlier posts on using these:

• Aug 08, 2011 : Are InnoDB Deadlocks exclusive to INSERT/UPDATE/DELETE?
• Jan 02, 2012 : LOCK IN SHARE MODE
• Mar 18, 2012 : select for update gives error on indexed column
• May 09, 2012 : Transaction Lock Timeouts When Updating a Row
• May 13, 2012 : Cannot update certain rows in innodb tables
• Aug 10, 2012 ; Similar function NOWAIT in MySQL

With regard to sessions and connections

• Performing SELECT ... FOR UPDATE will initiate locks on rows you intend to update and still permit other DB Connections to read.
• Performing SELECT ... LOCK IN SHARE MODE essentially does the reverse
• lock rows for you to read
• allow SELECTs of the same locked rows
• prevent connections from doing SELECT ... FOR UPDATE or direct DML

The only advantage I see in using these SELECT queries is too prevent needless deadlocks on pages.

I hope this helps !!!