From 6fb7af1b2b97edfe97c5a0d4a2a87dd2e871b3c0 Mon Sep 17 00:00:00 2001 From: Kirtan Kushwah Date: Sat, 7 Jan 2023 00:18:18 +0530 Subject: [PATCH 1/3] Update README.md --- README.md | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) diff --git a/README.md b/README.md index 14e1368..71001e9 100644 --- a/README.md +++ b/README.md @@ -1,10 +1,10 @@ -# DBMS_SQL_Overview +# DBMS SQL Overview ## DBMS 1 --> About DBMS ---> ER Diagram , Entity Set , Relationship , Cardinality Constraint , Attributes , Constraints +--> ER Diagram, Entity Set, Relationship, Cardinality Constraint, Attributes, Constraints --> Keys @@ -19,7 +19,7 @@ --> Types of Decomposition -##DBMS 2 +## DBMS 2 --> Normalization @@ -34,7 +34,7 @@ --> Relational Algebra -##DBMS 3 +## DBMS 3 --> SQL @@ -45,21 +45,14 @@ ## Deadlocks (Important): -A situation where a set of processes are blocked because each process is holding a -resource and waiting for another resource acquired by some other process. Deadlock -can arise if following four conditions hold simultaneously (Necessary Conditions): -1. Mutual Exclusion – One or more than one resource is non-sharable (Only one -process can use at a time). -2. Hold and Wait – A process is holding at least one resource and waiting for -resources. -3. No Preemption – A resource cannot be taken from a process unless the process -releases the resource. +A situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process. Deadlock can arise if following four conditions hold simultaneously (Necessary Conditions): + +1. Mutual Exclusion – One or more than one resource is non-sharable (Only one process can use at a time). +2. Hold and Wait – A process is holding at least one resource and waiting for resources. +3. No Preemption – A resource cannot be taken from a process unless the process releases the resource. 4. Circular Wait – A set of processes are waiting for each other in circular form. ● Methods for handling deadlock: There are three ways to handle deadlock -1. Deadlock prevention or avoidance : The idea is to not let the system into a -deadlock state. -2. Deadlock detection and recovery : Let deadlock occur, then do preemption to -handle it once occurred. -3. Ignore the problem all together : If deadlock is very rare, then let it happen and -reboot the system. This is the approach that both Windows and UNIX take. +1. Deadlock prevention or avoidance : The idea is to not let the system into a deadlock state. +2. Deadlock detection and recovery : Let deadlock occur, then do preemption to handle it once occurred. +3. Ignore the problem all together : If deadlock is very rare, then let it happen and reboot the system. This is the approach that both Windows and UNIX take. From 1dc999a00ee98c07333e3ca082939fb4e7b81616 Mon Sep 17 00:00:00 2001 From: Kirtan Kushwah Date: Sat, 7 Jan 2023 00:20:43 +0530 Subject: [PATCH 2/3] Update README.md --- README.md | 50 ++++++++++++++------------------------------------ 1 file changed, 14 insertions(+), 36 deletions(-) diff --git a/README.md b/README.md index 71001e9..99aa77a 100644 --- a/README.md +++ b/README.md @@ -1,47 +1,25 @@ # DBMS SQL Overview ## DBMS 1 ---> About DBMS - - ---> ER Diagram, Entity Set, Relationship, Cardinality Constraint, Attributes, Constraints - - ---> Keys - - ---> Functional Dependency - - ---> Decomposition of a Relation - - ---> Types of Decomposition + - About DBMS + - ER Diagram, Entity Set, Relationship, Cardinality Constraint, Attributes, Constraints + - Keys + - Functional Dependency + - Decomposition of a Relation + - Types of Decomposition ## DBMS 2 ---> Normalization - - ---> Transaction - - ---> Acid properties - - ---> Schedules - - ---> Relational Algebra + - Normalization + - Transaction + - Acid properties + - Schedules + - Relational Algebra ## DBMS 3 ---> SQL - - ---> DDL , DML , DCL - - ---> SQL queries + - SQL + - DDL , DML , DCL + - SQL queries ## Deadlocks (Important): From 925e191a14e1dcfe5e872b146e181e07f53cb449 Mon Sep 17 00:00:00 2001 From: Kirtan Kushwah Date: Sat, 7 Jan 2023 00:21:31 +0530 Subject: [PATCH 3/3] Update README.md --- README.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 99aa77a..8fdfb5c 100644 --- a/README.md +++ b/README.md @@ -23,14 +23,14 @@ ## Deadlocks (Important): -A situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process. Deadlock can arise if following four conditions hold simultaneously (Necessary Conditions): +A situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process. Deadlock can arise if following four conditions hold simultaneously (Necessary Conditions) : 1. Mutual Exclusion – One or more than one resource is non-sharable (Only one process can use at a time). 2. Hold and Wait – A process is holding at least one resource and waiting for resources. 3. No Preemption – A resource cannot be taken from a process unless the process releases the resource. 4. Circular Wait – A set of processes are waiting for each other in circular form. -● Methods for handling deadlock: There are three ways to handle deadlock + - Methods for handling deadlock: There are three ways to handle deadlock 1. Deadlock prevention or avoidance : The idea is to not let the system into a deadlock state. 2. Deadlock detection and recovery : Let deadlock occur, then do preemption to handle it once occurred. 3. Ignore the problem all together : If deadlock is very rare, then let it happen and reboot the system. This is the approach that both Windows and UNIX take.