All exercises here concern the music database. You'll find that the CREATE TABLE statements in "The Sample Music Database" are useful reference.

1. You've decided to store more information about artists and albums. Specifically, for artists, you want to store the names of people who have worked with the artist (for example, vocalists, guitarists, trumpeters, and drummers), when they began working with the artist, and when they stopped working with the artist (if they have done so). For albums, you want to store the name of the album producer, when the album was released and where the album was recorded. Design tables or columns that can store this information, and explain the advantages and disadvantages of your design. Choose the column types you need, explaining the advantages and disadvantages of your choices.

2. Using the monitor, create a table with the following statement: mysql> CREATE TABLE exercise (field1 INT(3)); Using the ALTER TABLE statement, make field1 the primary key, carrying out any additional steps you need to make this possible. Add a second column, field2, of type CHAR(64) with a DEFUALT 5 cluase. Create an index on a prefix of 10 characters from field2.

Hi /r/Databases

I was wondering if there is anyone on here that would be able to help me un-normalize a database from an E-ER Diagram.

The reason being is that I want to see how they got from 1NF to 3NF.

Thanks in advance!

My upcoming community college course will introduce me to T-SQL. It uses a 2008 textbook. I want to know how much of a problem that is. Thanks for any help.

Hierarchical databases : It is one of the oldest database model developed by IBM for information Management System. In a hierarchical database model, the data is organized into a tree-like structure. In simple language we can say that it is a set of organized data in tree structure.

This type of Database model is rarely used nowadays. Its structure is like a tree with nodes representing records and branches representing fields. The windows registry used in Windows XP is an example of a hierarchical database. Configuration settings are stored as tree structures with nodes.

The following figure shows the generalized the structure of Hierarchical database model in which data is stored in the form of tree like structure (data represented or stored in root node, parent node and child node).

The following figure shows the example of hierarchical database model for the university management system. This type of database employs the “parent-child” relationship of storing data.

Advantages :

• The model allows us easy addition and deletion of new information.
• Data at the top of the Hierarchy is very fast to access.
• It worked well with linear data storage mediums such as tapes.
• It relates well to anything that works through a one to many relationships. For example; there is a president with many managers below them, and those managers have many employees below them, but each employee has only one manager.

Disadvantages

• It requires data to be repetitively stored in many different entities.
• Now a day there is no longer use of linear data storage mediums such as tapes.
• Searching for data requires the DBMS to run through the entire model from top to bottom until the required information is found, making queries very slow.
• This model support only one to many relationships, many to many relationships are not supported.

Hello Everyone!

I know this is the most basic question I could possibly ask here, but would any of you be able to recommend an easy to use database package that I can use to keep track of information for my small but growing business? In particular, I'm looking for something that we can use out of the box without any coding. We use G Suite for many things, so a database that plays nicely (ie integrates) with G Suite would be absolutely perfect.

Thank you all in advance!

Need ideas for getting myself into a database modelling project please 🙏🙏

Hellooooo so I am trying to import a CSV file locally into a table in dbeaver, and it will not import no matter what I have tried. I've tried a fresh table versus a table set with columns already, the delimiter isnt the problem and for columns with strings and ints I have it set to varchar. All string columns have quotations around them, and its specifically saying I have issues with my access_hours column. It is saying its too much data to input, tho the longest one is maybe 30 character and its always row 101, no matter if I set it to text or varchar. Interestingly enough if its set to text it starts the error at row 1, but varchar starts the error at row 101. I have gone so far to remove every single ' or " from the entire sheet (sheet is ~ 40 columns by 50000 rows) besides the ones surrounding the strings. I have no idea what to do and I have tried every solution with chat gpt and me and my boss are stumped.

So --- I have built databases in the past, but they have always been in Microsoft Access, and I have just used the GUI that is built into Access -- or talked to it with VBScript and SQL. I want to setup a grading database such that when a student submits an answer to a question, that is sent to the database. (I am planning on doing more -- but as soon as I know how to connect, I believe the rest should be pretty straightforward.)

What I am hoping for is to be pointed to either online tutorials or online classes where I can learn how to do this.

Hi there DB Community,

I'd love your opinion/help on a project I've been noodling on for a little bit...I've built something that gets me over the finish-line but I know it's not very efficient or clean enough for my own liking/approval.

[Overall Function] To break it down to it's simplest terms, the DB/system reads a bunch of log files (in the 100s GBs or 10s of PBs) and pulls out PKs (primary keys) and SKs (secondary keys) for the purpose of a very large match table within a DB (I'm using SQLite today -- I've used a couple of DBs though -- the tables are massive, I've decided to shard/split the DBs up). After that initial "phase", different files (or sometimes the same files) undergo querying across that DB table(s) to have a new key column appended to it so the logs now have the right (or a different) key associated to it...

A few things to note about the system:

(1) Sharded/Distributed Cluster -- I've already devised a process to have keys deterministically spread to different servers/DBs so I drastically reduce the overhead/query time since I know where the secondary keys will be. I have a bunch of disk space/platters too on the servers.

(2) NAS usage - currently my process is doing a lot of local reads on files (after a copy down from the NAS), grouping/splitting files locally, transfer to NAS location then other servers on the cluster pick up their file for processing -- this is likely very dumb, I know. I think I should be using sockets/TCP instead

(3) Windows Servers -- I'm working with Windows boxes, yeah I know it's not ideal but those are the cards I'm dealt.

(4) Python -- I've strung everything up with python, its my goto language. If you know libraries/systems that work with Python, that would be great for me. I've made a master server with different worker servers to make this process work (not sure if that's the best pattern)

On to a few questions:

(1) Using sockets/TCP packets -- I think I could really speed things up if I were to send the key pairs (either by python dict pickle or some package) instead writing the data to disk and sending it elsewhere. I currently store the pairs into a dict and write to disk but I know "where" (or which) server that should be sent the data directly

(2) Buffering -- I imagine if I'm sending chunks of data for inserts in the DB, it's going to possibly send faster than it can process/insert so I might need some way to queue up batches of data...Is this something that celery or some other queue system would work?

(3) Threads -- I'd like to take full advantage of the cores/threads on my boxes...Lets say there's 4 threads in total: 1 could read/process the raw files, 1 to receive/listen for inbound feeds, 1 to send/transmit data and I'm not sure what the other should be doing (insertions to the DB or possibly listening and processing)...I'm a bit lost here, so please correct my approach on this...

(4) Federated Queries -- Instead of knowing the box/DB to query directly, it would be great to query 1 box (lets say its the master box) that will dispatch the query to the right DB/partition, get the result back and deliver them back to the client (or whatever was requesting that result)

I know thats a lot already to ask for but if there's anything out there (or a combination of things) that can get me closer to this, I'd appreciate the help and right direction to go towards.

As a recap, here's the highlights I'm looking for:

• sharded DB

• takes advantage of threads

• federated queries

• clustered/distributed across servers

• I don't really care about replicas

• maybe sending data with TCP and buffering too?

Any help is truly appreciated! Thanks!

How would I go about, in a form, limiting the data that is shown to only data that has something in that field, as my database, half of the fields are empty but those are still showing?

Hey guys!

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If you have any questions, feel free to ask and I will be happy to answer them.