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Usage of Float,Double and Decimal Data Types in MySql

When we start developing a database, we have to use the most appropriate data types for all the columns to store data values of the respective tables in it. For dealing with the floating type data values, most of the times, we get confused about which data type to go for, as we have Float, Decimal and Double as well. I, myself, as a new DBA, got confused about the usage of the same. So, i have re-searched through some websites over internet and have concluded some facts about these data types' usage. i want to share my experience with all of you.

What is Avro Schema

Avro schema generally used to define the data schema for a record's value. This schema describes the fields allowed in the value, along with their data types. We can apply a schema to the value portion of an Oracle NoSQL Database record using Avro bindings. These bindings are used to serialize values before writing them, and to deserialize values after reading them. The usage of these bindings requires our applications to use the Avro data format, which means that each stored value is associated with a schema. The use of Avro schemas allows serialized values to be stored in a very space-efficient binary format. Each value is stored without any metadata other than a small internal schema identifier, between 1 and 4 bytes in size. One such reference is stored per key-value pair. In this way, the serialized Avro data format is always associated with the schema used to serialize it, with minimal overhead. This association is made transparently to the application, and the internal sche

Difference between key-value stores and key-value pairs

Difference between key-value stores and key-value pairs or Difference between  Key-value stores  and document db or Difference between Redias and mongoDb .   Key Values always Conf us ed me that's why i decided to share my some short of experience , In NoSQL Databases KV Pair and KV Stores are different. Event they are related to different database vendors too. Key-Value stores ; store keys value pairs  in buckets, exactly like a hash table data structure; where each key must be unique.  They are extremely fast for writing, and extremely fast for reading and updating. if you have the key.  They are slow on multiple updates and if you have to query the entire store.  You see Key-value stores used a lot as caching stores because of their fast reads. eg: Redis, Riak, memcached, Azure's tablestore, etc Document Stores ; store data in "documents", typically XML or JSON documents. They're typically schema-less, so each document can contain any data that you want

First Day with Neo4j Graph Database

Hi friends, 2015 is the year when I started working on noSQL databases, I have shared my few post earlier on same . Today my post is related to one more nosql database which came into my skill recently. This is a popular Graph Database Neo4j. Neo4j is a popular noSQL, open-source, graph database which is implemented in Java and accessible from software written in other languages using CQL. Neo4j Support ACID. What is Graph Database ? In computing, a graph database is a database that uses graph structures for semantic queries with nodes, edges and properties to represent and store data. Graph databases employ nodes, properties, and edges.

Two way to execute javaScript in mongod

Hi friends, We can automate things of mongdb using javascript procedures . Mongodb allows to execute javaScript through two ways . This post will demonstrate how to automate mongodb administration work. First of all write mongodb queries or procedure, which we have to performe and then save into .js file and then consider any process out of below 2. 1.) We can execute from command shell, without login mongo shell. So we can schedule script of administering tasks that will run automatically like below : c:\>mongo localhost:27017/test admin.js This operation executes the admin.js script in a mongo shell that connects to the test database on the mongod instance accessible via the localhost interface on port 27017. 2.) We can execute a .js file from within the mongo shell, using the load() function, as in the following: load("admin.js") Thanks for reading

3 ways to recompile stored procedures

Requirement for Recompilation :  When we create and execute a procedure it will compiled and create execution plan for the present state of the database . If we do changes into database structure, we should recompiling a procedure updates and optimizes the procedure’s query plan for those changes. This can improve the procedure’s processing performance. Another reason to stress a procedure to recompile is to retro-act the "parameter sniffing". When SQL Server executes procedures, any parameter values that are used by the procedure when it compiles are connected as part of generating the query plan. SQL Server also do automatic recompiling of procedure whenever Server is restarted. 3 ways to recompile manually : 1.) Directly writing in procedure. 2.) During execution of procedure. 3.) Ad-hoc manner from query prompt. Directly writing in procedure. Create PROCEDURE [dbo] . [upTitle_Select] @TitleID int = NULL, @Title varchar ( 5 ) = NUL

SQL71562: external references are not supported when creating a package from this platform

Last week I got this error from one of developer who was trying to deploy his project from Testing server to SQL Azure QA server. He was using “Deploy Database to SQL Azure” option from SSMS Tool-Task option. After connecting to SQL Azure portal when operation started to deployment below errors occurs. Validation of the schema model for data package failed. Error SQL71562: Error validating element xx.xxx.xx:function .dbo.xxx has an unresolved refrence to object xx.dbo.xxxx external refrences are not supported when creating a package from this platform . Reason: The reason of the this error was; some functions of project was dependent on master database and only single database was being deploy to SQL Azure. DACFx must block Export when object definitions (views, procedures, etc.) contain external references, as Azure SQL Database does not allow cross-database external references So, this error was coming. Solution : I suggested him to create those function to locally