This time , in this first part ,we will go deeper by checking the different key type<\/strong> ,how to use it and their limitation.<\/p>\n\n\n\n So let’s go!<\/p>\n\n\n\n As a reminder,let’s take a look again on the major advantages of using a Redis database:<\/p>\n\n\n\n Redis keys are binary safe, this means that you can use any binary sequence as a key, from a string like “foo” to the content of a JPEG file. The empty string is also a valid key.<\/strong><\/p>\n\n\n\n Best practice about keys:<\/span><\/p>\n\n\n\n Of course I invite you to visit Redis site<\/strong> which is really complete and useful ( also a lot of Redis item definition you will find here are extracted from the Redis official site itself.)<\/p>\n\n\n\n Below you will see all Key Type you can find on Redis ( I used RedisInsight <\/strong>to show you that )<\/p>\n\n\n\n Note that the commands are not case sensitive , in other words a HSET <\/strong>and a hset <\/strong>or HSeT <\/strong>will give the same result \ud83d\ude42<\/p>\n\n\n\n We will list them and give:<\/p>\n\n\n\n Hashes are record types structured as collections of field-value pairs. You can use hashes to represent basic objects and to store groupings of counters, among other things.<\/p>\n\n\n\n Every hash can store up to 4,294,967,295<\/strong> (2^32 – 1) field-value pairs. In practice, your hashes are limited only by the overall memory on the VMs hosting your Redis deployment<\/strong>.<\/p>\n\n\n\n Redis allows you to associate an ordered sequence of strings to a key. This linked list of strings<\/strong> lets you perform a set of operations such as:<\/p>\n\n\n\n Basic commands<\/strong><\/p>\n\n\n\n A Redis set is an unordered collection of unique strings (members). You can use Redis sets to efficiently:<\/p>\n\n\n\n Basic commands<\/strong><\/p>\n\n\n\n Example:<\/strong><\/p>\n\n\n\n The max size of a Redis set is 2^32 – 1 (4,294,967,295<\/strong>) members.<\/p>\n\n\n\n A Redis sorted set is a collection of unique strings (members) ordered by an associated score. When more than one string has the same score, the strings are ordered lexicographically. Some use cases for sorted sets include:<\/p>\n\n\n\n Basic commands<\/strong><\/p>\n\n\n\n Example<\/strong><\/p>\n\n\n\n Note:<\/span><\/strong><\/p>\n\n\n\n Using ZREVRANK <\/strong>will display the rank of user from the highest score to the lowest , also first rank will start with 0<\/strong><\/p>\n\n\n\n Redis strings store sequences of bytes, including text, serialized objects, and binary arrays. As such, strings are the most basic Redis data type. They’re often used for caching, but they support additional functionality that lets you implement counters and perform bitwise operations, too.<\/p>\n\n\n\n Basic Commands<\/strong><\/p>\n\n\n\n Limits <\/strong><\/p>\n\n\n\n By default, a single Redis string can be a maximum of 512 <\/strong>MB.<\/p>\n\n\n\n We have seen some of useful Redis command to create keys and play with it , there is some other remaining but we will see that in another post.<\/p>\n\n\n\n For the moment I invite you to share with us , visit the dbi bloggers<\/a> and also to check my other blogs<\/a> for Control-M or Jenkins for example :).<\/p>\n\n\n\n Stay tuned for the part 2<\/strong>!<\/p>\n","protected":false},"excerpt":{"rendered":" Introduction: Hi team , we have seen during previous posts, how is working Redis , how to browse into data using Redis Insight and how to backup your database. This time , in this first part ,we will go deeper by checking the different key type ,how to use it and their limitation. So let’s […]<\/p>\n","protected":false},"author":40,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1739],"tags":[],"type_dbi":[],"class_list":["post-24986","post","type-post","status-publish","format-standard","hentry","category-nosql"],"acf":[],"yoast_head":"\nAbout Redis<\/h2>\n\n\n\n
![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD1-1024x242.png\")
<\/figure>\n\n\n\nKeys<\/h2>\n\n\n\n
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The different Key type<\/h2>\n\n\n\n
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![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD.png\")
<\/figure>\n\n\n\nHash Type <\/h2>\n\n\n\n
Basic commands<\/h4>\n\n\n\n
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HSET<\/strong><\/code><\/a> sets the value of one or more fields on a hash.<\/li>\n\n\n\nHGET<\/strong><\/code><\/a> returns the value at a given field.<\/li>\n\n\n\nHMGET<\/strong><\/code><\/a> returns the values at one or more given fields.<\/li>\n\n\n\nHINCRBY<\/strong><\/code><\/a> increments the value at a given field by the integer provide<\/li>\n\n\n\nHGETALL<\/code> <\/a><\/strong>\u2013 Displays the entire hash content.<\/li>\n\n\n\nHDEL<\/code><\/strong> <\/a>\u2013 Removes an existing key-value pair from a hash.<\/li>\n<\/ul>\n\n\n\nExample<\/h4>\n\n\n\n
![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/image-3.png\")
<\/figure>\n\n\n\nLimits<\/h4>\n\n\n\n
Lists<\/h2>\n\n\n\n
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LPUSH<\/code><\/a> <\/strong>adds a new element to the head of a list; RPUSH<\/code><\/a> adds to the tail.<\/li>\n\n\n\nLPOP<\/code><\/a> <\/strong>removes and returns an element from the head of a list; RPOP<\/code><\/a> does the same but from the tails of a list.<\/li>\n\n\n\nLLEN<\/code><\/a> <\/strong>returns the length of a list.<\/li>\n\n\n\nLMOVE<\/code><\/a> <\/strong>atomically moves elements from one list to another.<\/li>\n\n\n\nLTRIM<\/code><\/a> <\/strong>reduces a list to the specified range of elements.<\/li>\n\n\n\nRPUSH<\/code><\/strong> <\/a>\u2013 Pushes the value to the tail end of the list.<\/li>\n\n\n\nLRANGE<\/code><\/strong> <\/a>\u2013 Retrieves a range of items.<\/li>\n\n\n\nLPOP<\/a>\/<\/code>RPOP<\/code> <\/a><\/strong>\u2013 Used to display and remove items from both ends.<\/li>\n\n\n\nLINDEX<\/code> <\/a><\/strong>\u2013 Obtain a value from a specific position within the list.<\/li>\n<\/ul>\n\n\n\n![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD3.png\")
<\/figure>\n\n\n\nSets<\/h2>\n\n\n\n
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SADD<\/code><\/a> <\/strong>adds a new member to a set.<\/li>\n\n\n\nSREM<\/code><\/a> <\/strong>removes the specified member from the set.<\/li>\n\n\n\nSISMEMBER<\/code><\/a> <\/strong>tests a string for set membership.<\/li>\n\n\n\nSINTER<\/code><\/a> <\/strong>returns the set of members that two or more sets have in common (i.e., the intersection).<\/li>\n\n\n\nSCARD<\/code><\/a> <\/strong>returns the size (a.k.a. cardinality) of a set.<\/li>\n\n\n\nSMEMBERS<\/code><\/strong> <\/a>\u2013 Retrieves all items from a set.<\/li>\n<\/ul>\n\n\n\n![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD4-1024x374.png\")
<\/figure>\n\n\n\nLimits<\/h4>\n\n\n\n
Sorted sets<\/h2>\n\n\n\n
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ZADD<\/code><\/a> <\/strong>adds a new member and associated score to a sorted set. If the member already exists, the score is updated.<\/li>\n\n\n\nZRANGE<\/code><\/a> <\/strong>returns members of a sorted set, sorted within a given range.<\/li>\n\n\n\nZRANK<\/code><\/a> <\/strong>returns the rank of the provided member, assuming the sorted is in ascending order.<\/li>\n\n\n\nZREVRANK<\/code><\/a> <\/strong>returns the rank of the provided member, assuming the sorted set is in descending order.<\/li>\n\n\n\nZRANGEBYSCORE <\/a><\/code><\/strong>\u2013 Fetches items from the sorted set based on the defined score range. The withscores<\/code> <\/strong>option produces the actual score values.ZREM<\/code> \u2013<\/strong> Removes items from a sorted set.<\/li>\n<\/ul>\n\n\n\n\n
![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD5-1024x482.png\")
<\/figure>\n\n\n\n\n
![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD7-1024x551.png\")
<\/figure>\n\n\n\n\n
![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD8.png\")
<\/figure>\n\n\n\n![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD9.png\")
<\/figure>\n\n\n\nStrings<\/h2>\n\n\n\n
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SET<\/code><\/a> <\/strong>stores a string value.<\/li>\n\n\n\nSETNX<\/code><\/a> <\/strong>stores a string value only if the key doesn’t already exist. Useful for implementing locks.<\/li>\n\n\n\nGET<\/code><\/a> <\/strong>retrieves a string value.<\/li>\n\n\n\nMGET<\/code><\/a> <\/strong>retrieves multiple string values in a single operation<\/li>\n<\/ul>\n\n\n\n![\"\"](\"https:\/\/www.dbi-services.com\/blog\/wp-content\/uploads\/sites\/2\/2023\/05\/REDISCMD91.png\")
<\/figure>\n\n\n\nConclusion<\/h2>\n\n\n\n