Integrity Constraints and Domain Constraints
Integrity constraints ensure that changes made to the database by authorized users do not lead to loss of data consistency. Integrity means something like 'be right' and consistent. The data which are in a database must be right and in good condition. Domain Constraints refer to the domain of possible values that must be associated with every attribute in the database. Declaring an attribute of a particular domain acts as a restraint on the values it can take. These constraints are easily tested by the system. There are the data integrity, domain integrity, attribute integrity, the entity integrity and the referential integrity constraints. The data is used to create information which is needed for making decisions. Therefore, we need to make sure that the data which is stored in the database is correct and consistent. This is referred to as data integrity. For relational database integrity there are entity integrity and referential integrity rules which help to make sure that we have data integrity. Domain integrity means the definition of a valid set of values for an attribute. In domain integrity we define the data types, length or size, whether the null value allowed or not, either the value is unique or not for an attribute. Attribute integrity is not part of the relational model. It is used by database software to help with data integrity. The software makes sure that data for particular fields is of the correct type for example letters or numbers or the correct length. The entity integrity rule is applied to Primary Keys. The entity integrity rule says that the value of a Primary key in a table must be unique and it can never have null values. The referential integrity key is applied to Foreign Keys. A relation schema may have an attribute which corresponds to the primary key of another relation. The attribute is called a foreign key. The referential integrity key says that the value of a Foreign key must either be null or be equal to the value in the linked table where the Foreign key is the primary key.
Summary
Integrity constraints ensure that changes made to the database by authorized users do not lead to loss of data consistency. Integrity means something like 'be right' and consistent. The data which are in a database must be right and in good condition. Domain Constraints refer to the domain of possible values that must be associated with every attribute in the database. Declaring an attribute of a particular domain acts as a restraint on the values it can take. These constraints are easily tested by the system. There are the data integrity, domain integrity, attribute integrity, the entity integrity and the referential integrity constraints. The data is used to create information which is needed for making decisions. Therefore, we need to make sure that the data which is stored in the database is correct and consistent. This is referred to as data integrity. For relational database integrity there are entity integrity and referential integrity rules which help to make sure that we have data integrity. Domain integrity means the definition of a valid set of values for an attribute. In domain integrity we define the data types, length or size, whether the null value allowed or not, either the value is unique or not for an attribute. Attribute integrity is not part of the relational model. It is used by database software to help with data integrity. The software makes sure that data for particular fields is of the correct type for example letters or numbers or the correct length. The entity integrity rule is applied to Primary Keys. The entity integrity rule says that the value of a Primary key in a table must be unique and it can never have null values. The referential integrity key is applied to Foreign Keys. A relation schema may have an attribute which corresponds to the primary key of another relation. The attribute is called a foreign key. The referential integrity key says that the value of a Foreign key must either be null or be equal to the value in the linked table where the Foreign key is the primary key.
Things to Remember
- Integrity constraints ensure that changes made to the database by authorized users do not lead to loss of data consistency. Integrity means something like 'be right' and consistent. The data which are in a database must be right and in good condition.
- Domain Constraints refer to the domain of possible values that must be associated with every attribute in the database. Declaring an attribute of a particular domain acts as a restraint on the values it can take.
- There are the data integrity, domain integrity, attribute integrity, the entity integrity and the referential integrity constraints.
- The data is used to create information which is needed for making decisions. Therefore, we need to make sure that the data which is stored in the database is correct and consistent. This is referred to as data integrity.
- Domain integrity means the definition of a valid set of values for an attribute. In domain integrity we define the data types, length or size, whether the null value allowed or not, either the value is unique or not for an attribute.
- Attribute integrity is not part of the relational model. It is used by database software to help with data integrity.
- The entity integrity rule is applied to Primary Keys. The entity integrity rule says that the value of a Primary key in a table must be unique and it can never have null values.
- The referential integrity key is applied to Foreign Keys. A relation schema may have an attribute which corresponds to the primary key of another relation. The attribute is called a foreign key. The referential integrity key says that the value of a Foreign key must either be null or be equal to the value in the linked table where the Foreign key is the primary key.
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Subjective Questions
Q1:
What are the types of anesthesia?
Type: Short Difficulty: Easy
<li>General anesthesia: The patient is sedated, using either intravenous medication or gaseous substances, and muscle paralysed, requiring control of breathing by mechanical ventilation.</li>
<li>Regional anesthesia: This can be describe as central where anesthetic drugs are cord, blocking the nerves of the spinal cord. The Main of this method in that ventilation is not needed. It can also be peripheral such as:</li>
<li>Plexus blocks, e.g. brachial plexus</li>
<li>Nerve block, e.g. femoral</li>
<li>Intravenous block, e.g. Bier’s block</li>
<li>Local anesthesia: The anesthetic is applied to one site, usually topically or subcutaneously. Drugs used for local anesthesia are:</li>
<li>Procaine 1-2%solution, used for injection</li>
<li>Lignocaine 0.5-2% injection and topical application</li>
<li>Benzocaine 5% used as ointment on painful wounds, skin ulcers, mucous membrane.</li>
</ul>
Q2:
Write the Stages of anesthesia ?
Type: Short Difficulty: Easy
<li>Stages 1anesthesia: It is also known as the induction is the period between the initial administration of the induction agents and losses of consciousness. During this stage, the patient progress from analgesia without amnesia to analgesia with amnesia. Patient may carry on a conversation at this time.</li>
<li>Stage 2 anesthesias: also known as excitement stage is the period following loss of consciousness and marked by excited and delirious activity. During this stage, respiration and heart rate may be irregular. In addition, there may be uncontrolled movements, vomiting, breath holding, and irregular respiration may lead to airway compromise, rapidly acting drugs are used to minimize time in this stage and reach stage 3 as fast as possible.</li>
<li>Stage 3 anesthesia: it is surgical anesthesia. During this stage, the skeletal muscles relax and the patients breathing become regular. Eye movement will be slow, then stop and surgery can began. It has been divided into 4 planes:</li>
</ol>
<ul>
<li>Rolling eye balls, ending with fixed eyeballs.</li>
<li>Loss of corneal and laryngeal reflexes</li>
<li>Pupils dilates and loss of light reflex</li>
<li>Intercostals paralysis, shallow abdominal respiration, dilated pupils</li>
</ul>
<ol>
<li>Stage 4 anesthesia: It is also known as over dose where too much medicine has been given relative to the amount of surgical stimulation and the patient has severe brain stem or medullar depression. This results in cessations of respiration and potential cardiovascular collapse. This stage is lethal without cardiovascular and respiratory support.</li>
</ol>
Q3:
Write the Nursing care of anesthetic patient ?
Type: Long Difficulty: Easy
<ul>
<li>Monitor the patient’s ECG, heart rate, SPO2continously to be measured oxygen level in the blood.</li>
<li>Monitor vital signs i.e. blood pressure, heart rate, respiratory rate regularly and record appropriately.</li>
<li>Monitor the patient’s level of consciousness and provide oxygen therapy.</li>
<li>Maintain airway e.g. positioning the patient and suctioning if necessary. Maintain side lying position to prevent aspiration after general anesthesia.</li>
<li>Maintain body temperature and keeps patients warm. Measure temperature frequently to observe hypothermia or fever.</li>
<li>Assess for allergies and other medical problems that may occur after the client’s response to the anesthetic agent.</li>
<li>Keeps oxygen emergency resuscitation equipment available and proper working condition.</li>
<li>Maintain a calm and quite environment during induction anesthesia.</li>
<li>Protect the client from mechanical/ thermal injury during this period because of decreased sensory awareness.</li>
<li>Keep client flat for a specific period usually 12 hours after spinal anesthesia to protect the severe headache, avoid pillow, monitor for hypotension.</li>
<li>Use safety precautions and maintain bed rest until motor and sensory function return of lower extremities after spinal anesthesia, maintain input and output chart strictly.</li>
<li>Oral intake is usually given after 12 hours of the general anesthesia and after the ability to swallow is returned.</li>
<li>Prevent the patient from falling by keeping the side rails up, never leave alone.</li>
<li>Maintain the record and report the type of anesthesia given.</li>
<li>Observe for side effects and complications o</li>
</ul>
Q4:
What are the Complications of anesthesia ?
Type: Long Difficulty: Easy
<ol>
<li>Complication of general anesthesia</li>
<li>Anaphylaxis</li>
</ol>
<ul>
<li>It can occur to any anesthetic agent and in all types of anesthesia.</li>
<li>The severity of reaction may vary but features may include rashes, urticaria, hypotension, angio edema and vomiting.</li>
<li>Patients who are suspected of an allergic reaction should be referred for further investigation to try to determine the exact cause.</li>
</ul>
<ol>
<li>Aspiration pneumonitis</li>
</ol>
<ul>
<li>A reduced level of consciousness can lead to an unprotected airway.</li>
<li>If the patient vomits they can aspirate the vomitus content into their lungs. This can setup lung inflammation with infection.</li>
</ul>
<ol>
<li>Peripheral nerve damage</li>
</ol>
<ul>
<li>This can occur with all types of anesthesia and results for nerve compression.</li>
<li>The most common cause is exaggerated positioning for prolonged periods of time.</li>
<li>The most common nerves affected are the ulnar and the common peroneal nerve.</li>
</ul>
<ol>
<li>Damage to teeth</li>
</ol>
<ul>
<li>It is most common cause of claims made against anesthetics.</li>
<li>The tooth most commonly affected is the upper left incisor.</li>
</ul>
<p> </p>
<ol>
<li>Embolism</li>
</ol>
<ul>
<li>It is rare during anesthetic but is potentially fatal.</li>
<li>It occur more commonly during neurosurgical procedures or pelvic operation.</li>
</ul>
<ol start="2">
<li>Some specific complication of regional anesthesia</li>
<li>Post-dural puncture headache</li>
</ol>
<ul>
<li>It is very common after spinal anesthesia and especially in young adults and obstetrics.</li>
<li>The headache result from CSF leak from the puncture site. It is enhanced by use of larger gauze needle and reduced by pencil tipped needles.</li>
<li>Presenting symptoms may include headache, photophobia, vomiting nad dizziness.</li>
</ul>
<ol>
<li>Total spinal block</li>
</ol>
<ul>
<li>It can occur with the injection of large amount of anesthetic agents into spinal cord.</li>
<li>It is detected by a high sensory level and rapid muscle paralysis.</li>
</ul>
<ol>
<li>Hypotension</li>
</ol>
<ul>
<li>This usually responds to prompt fluid replacement, usually starting with crystalloids followed by collides.</li>
<li>Care must be taken in patients with a cardiac history as they may develop myocardial ischemia with minor drops in blood pressure.</li>
</ul>
<ol>
<li>Neurological deficits</li>
</ol>
<ul>
<li>This is common reason for patient to refuse spinal anesthesia.</li>
<li>There may also be traumatic injury to the spinal cord.</li>
</ul>
<ol start="3">
<li>Important complication of local anesthesia</li>
</ol>
<ul>
<li>Pain</li>
<li>Bleeding and haematoma formation</li>
<li>Nerve injury due to direct injury</li>
<li>Infection</li>
<li>Ischaemic necrosis</li>
</ul>
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Integrity Constraints and Domain Constraints
Integrity Constraints and Domain Constraints
Integrity constraints ensure that changes made to the database by authorized users do not lead to loss of data consistency. Integrity means something like 'be right' and consistent. The data which are in a database must be right and in good condition.
Domain Constraints refer to the domain of possible values that must be associated with every attribute in the database. Declaring an attribute of a particular domain acts as a restraint on the values it can take. These constraints are easily tested by the system. EX1: cannot set an integer variable to "cat".
There are the data integrity, domain integrity, attribute integrity, the entity integrity and the referential integrity constraints.
Data Integrity
The data is used to create information which is needed for making decisions. Therefore, we need to make sure that the data which is stored in the database is correct and consistent. This is referred to as data integrity. For relational database integrity, there are entity integrity and referential integrity rules which help to make sure that we have data integrity.
Domain Integrity
Domain integrity means the definition of a valid set of values for an attribute. In domain integrity, we define the data types, length or size, whether the null value allowed or not, either the value is unique or not for an attribute. We may also define the default value, the range that is valued in between and/or specific values for the attribute. Some DBMS allow us to define the output format and/or input mask for the attribute.
These definitions ensure that a specific attribute will have a right and proper value in the database.
Attribute Integrity
Attribute integrity is not part of the relational model. It is used by database software to help with data integrity. The software makes sure that data for particular fields is of the correct type for example letters or numbers or the correct length.
Entity Integrity
The entity integrity rule is applied to Primary Keys. The entity integrity rule says that the value of a Primary key in a table must be unique and it can never have null values. Operations on the database such as inserting new data, updating the existing data and deleting data must follow this rule.
Referential Integrity
The referential integrity key is applied to Foreign Keys. A relation schema may have an attribute which corresponds to the primary key of another relation. The attribute is called a foreign key. The referential integrity key says that the value of a Foreign key must either be null or be equal to the value in the linked table where the Foreign key is the primary key. Ensuring that a value that appears in one relation for a given set of attributes also appear for a certain set of attributes in another relation. EX1: In a banking system, the attribute branch-name in Account-Schema is a foreign key referencing the primary key of Branch-Schema.
References:
- H.F.Korth and A. Silberschatz,"Database system concepts",McGraw Hill,2010
- A.K.Majumdar and p, Bhatt acharya,"Database Management Systems",Tata McGraw Hill,India,2004
- F.Korth, Henry. Database System Concepts. 6th edition.
Lesson
Database Constraints and Normalization
Subject
Computer Engineering
Grade
Engineering
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