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Questions tagged [rdbms]

A relational database management system (RDBMS) is a database management system (DBMS) in which data is stored in tables and the relationships among the data are also stored in tables.

A relational database management system (RDBMS) is a database management system () that is based on the relational model as introduced by E. F. Codd, of IBM's San Jose Research Laboratory. Many popular databases that are currently in use are based on the relational database model.

RDBMSs have become a predominant choice for the storage of information in new databases used for financial records, manufacturing and logistical information, personnel data, and much more. Relational databases have often replaced legacy hierarchical databases and network databases because they are easier to understand and use. However, relational databases have been challenged by object databases, which were introduced in an attempt to address the object-relational impedance mismatch in relational database, and XML databases.

History:
The development for the RDBMS model began at in 1974
The first commercially available RDBMS system was in 1979
The first RDBMS system for Mac OS was in 1984

References:

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Standard use of 'Z' instead of NULL to represent missing data?

Outside of the argument of whether or not NULLs should ever be used: I am responsible for an existing database that uses NULL to mean "missing or never entered" data. It is different from empty string, which means "a user set this value, and they…
Boris Nikolaevich
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Why is Solr so much faster than Postgres?

I recently switched from Postgres to Solr and saw a ~50x speed up in our queries. The queries we run involve multiple ranges, and our data is vehicle listings. For example: "Find all vehicles with mileage < 50,000, $5,000 < price < $10,000,…
cberner
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What does the term "Tuple" Mean in Relational Databases?

Please explain what is meant by tuples in sql?Thanks..
Warrior
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When to use CouchDB vs RDBMS

I am looking at CouchDB, which has a number of appealing features over relational databases including: intuitive REST/HTTP interface easy replication data stored as documents, rather than normalised tables I appreciate that this is not a mature…
Andrew Whitehouse
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How should international geographical addresses be stored in a relational database?

Given the task of storing international geographic addresses in a relational table, what is the most flexible schema? Should every part of the address be broken out into their own fields, or should it be more like free text? Is there any sense in…
Bob
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Why isn't RDBMS Partition Tolerant in CAP Theorem and why is it Available?

Two points I don’t understand about RDBMS being CA in CAP Theorem : 1) It says RDBMS is not Partition Tolerant but how is RDBMS any less Partition Tolerant than other technologies like MongoDB or Cassandra? Is there a RDBMS setup where we give up CA…
Glide
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Why are batch inserts/updates faster? How do batch updates work?

Why are batch inserts faster? Is it because the connection and setup overhead for inserting a single row is the same for a set of rows? What other factors make batch inserts faster? How do batch updates work? Assuming the table has no uniqueness…
letronje
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Best practices on primary key, auto-increment, and UUID in SQL databases

We're designing a table for user entity. The only non-trivial requirement is that there should be a permanent URL to the user entity (for example their profile). There's a lot about int/long vs UUID on the web. But it is still unclear to me. …
Rad
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Create an inline SQL table on the fly (for an excluding left join)

Let's assume the following: Table A id | value ---------- 1 | red 2 | orange 5 | yellow 10 | green 11 | blue 12 | indigo 20 | violet I have a list of id's (10, 11, 12, 13, 14) that can be used to look up id's in this table. This list of…
rinogo
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How many significant digits should I store in my database for a GPS coordinate?

I have in my MySQL database both longitude and latitude coordinates (GPS data). It's currently stored as: column type ------------------------ geolat decimal(10,6) geolng decimal(10,6) Question: Do I really need a data type as large as…
teddyk
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What is the difference between DBMS and RDBMS?

What is the key difference between a DBMS and RDBMS and any relation between them?
haccks
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How to detect duplicate rows in a SQL Server table?

What is the most efficient way to detect duplicates in a 10 column / 50K row table? I'm using MSSQL 8.0
Bajji
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Two foreign keys referencing the same primary key

Is this okay to have two foreign keys in one table referencing one primary key of other table? EmployeeID is a primary key in the employee table and appearing as a foreign key twice in the timesheet table. There will be few admin users filling up…
user1263981
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SQL Server Insert Example

I switch between Oracle and SQL Server occasionally, and often forget how to do some of the most trivial tasks in SQL Server. I want to manually insert a row of data into a SQL Server database table using SQL. What is the easiest way to do that? For…
n00b
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What's the correct name for an "association table" (a many-to-many relationship)

What's the correct or most popular name for an "association table"? I've heard lookup, associative, resolving, mapping and junction table.
Imran
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