In our case, Australia Zoo Wildlife Hospital (AZWH) is a charity organization that exists to treat and or care for sick, injured or orphaned wildlife where by a lot of data is required to be collected and stored. Identification of different wildlife species which are brought, for treatment, to make monitoring easy by referring to that information collected and also to enable the organization to make decisions.
In the existing database system there are few implementation flaws that may lead to poor performance (Bonner, Kifer and Consens, 2009):
Lack of identifying primary keys in different tables
For a good performance and a high speed querying, a primary key should be set in database tables. They are set as unique such that there isn’t any other column that can have the same. In relational databases, primary keys are supposed to be the first priorities which help the tables to link through foreign keys (Dearie et al., 2010).
For instance, azwh_accessions table should have an accession_number column set as a primary key which is unique to every animal. The accession_number value will then be put in the azwh_carer_groups table as a foreign key to link azwh_accessions table and azwh_carer_groups.
Redundant data due to poor management
Generally, redundancy is a good feature when it comes to backing up of data ,just in case one location get compromised and data is lost the same data may be retrieved from another location. However, when designing databases, it is not a good practice to repeat data in different table locations. When different tables have same data set, it’s an indication that normalization rules are not adhered to. Others repeat table data in different tables to increase convenience.
In our case, permit_number data column in azwh_carer_permits is still repeated in azwh_carrer_groups table which should not be the case.This is a poor data redundancy design. Instead the two tables can be linked together using primary keys and foreign keys relationship. Where by azwh_carer_permits table should have carer_group_id as a primary key and as a foreign key in the azwh_carer_groups table.
The length of some columns in the table.
The length is also referred to as the value size. Mostly, columns with varchar or text with data types, they may have unpredictable inputs which may vary in length. Where there is a text data type shows that there might be a description needed (Ghandeharizadeh, Hull and Jacobs, 2011). Some people usually set length which is not a good thing because the user may want to give a description which may be longer than the specified length thus syntax error. So it is advisable not to specify the length when the data type is text.
For the case of a varchar data type, it’s a must to set the length/size of the values .If you set a short length then the input is longer, that’s a syntax error.For instance, in table azwh_permit_types the length of the column name that is set to 50, yet user may have a longer name length. Also in table azwh_contact_categories name column is given a short length
Indexes
Basically, indexing is used in situations where by the data columns are many and the need to query them. When database table is has many columns, the use of SELECT to query the table columns becomes inefficient in terms of time response/speed. For a better performance while using index, the data type matters (Karwin, 2010). When index is on columns with data type in the performance is better than the performance while index is on columns with data types such as: varchar, date or decimal.
So having an index which is different from the primary key on all table columns make the querying more efficient in creating, reading ,deleting and updating operations than when having an index in every single column. However, when indexing is overdone, the performance is bad.
Use of UNIQUE constraint –
Every animal in the hospital is being given a patient id which should be different from the other animals (Leontiev, Özsu and Szafron, 2012). So uniqueness maybe applied by use of UNIQUE constraint. The azwh_accessions table is altered to add UNIQUE constraint Existing Database System: ER
Conclusion
As already stated above database should be well planned before even thinking about coding. In most cases database designers may de-normalize the database to increase performance which in turn will be ignoring normalization rules.
While designing a database, it should be designed such that, when the data to be stored increases, the efficiency is still good. Because the larger the database the more complex it is, so if not well designed some functionalities becomes less efficient thus poor performance.
References
Bonner, A.J., Kifer, M. and Consens, M., 2009. Database programming in transaction logic. In Database Programming Languages (DBPL-4) (pp. 309-337). Springer, London.
Dearie, A., Connor, R.C.H., Brown, A.L. and Morrison, R., 2010. NapierSS-A Database Programming Language?. In Proceedings of the Second International Workshop on Database Programming Languages, 4-8 June 1989 Salishan Lodge, Gleneden, Beach, Oregon (p. 179). Morgan Kaufmann.
Ghandeharizadeh, S., Hull, R. and Jacobs, D., 2011. Heraclitus: Elevating deltas to be first-class citizens in a database programming language. ACM Transactions on Database Systems (TODS), 21(3), pp.370-426.
Karwin, B., 2010. SQL antipatterns: avoiding the pitfalls of database programming. Pragmatic Bookshelf.
Leontiev, Y., Özsu, M.T. and Szafron, D., 2012. On type systems for object-oriented database programming languages. ACM Computing Surveys (CSUR), 34(4), pp.409-449.
Essay Writing Service Features
Our Experience
No matter how complex your assignment is, we can find the right professional for your specific task. Contact Essay is an essay writing company that hires only the smartest minds to help you with your projects. Our expertise allows us to provide students with high-quality academic writing, editing & proofreading services.
Free Features
Free revision policy
$10Free bibliography & reference
$8Free title page
$8Free formatting
$8How Our Essay Writing Service Works
First, you will need to complete an order form. It's not difficult but, in case there is anything you find not to be clear, you may always call us so that we can guide you through it. On the order form, you will need to include some basic information concerning your order: subject, topic, number of pages, etc. We also encourage our clients to upload any relevant information or sources that will help.
Complete the order form
Once we have all the information and instructions that we need, we select the most suitable writer for your assignment. While everything seems to be clear, the writer, who has complete knowledge of the subject, may need clarification from you. It is at that point that you would receive a call or email from us.
Writer’s assignment
As soon as the writer has finished, it will be delivered both to the website and to your email address so that you will not miss it. If your deadline is close at hand, we will place a call to you to make sure that you receive the paper on time.
Completing the order and download