Styjun

Phonetic distortion when words are borrowed among languages

Creating specific options in `Manipulate[]`

The differences amongst f[x_], f[x__], and f[x___]

How do my husband and I get over our fear of having another difficult baby?

Booting Ubuntu from USB drive on MSI motherboard -- EVERYTHING fails

French license plates

Beyond Futuristic Technology for an Alien Warship?

What is the logical distinction between “the same” and “equal to?”

How important is knowledge of trig identities for use in Calculus

How to stop the death waves in my city?

How to study endgames?

Why isn't there armor to protect from spells in the Potterverse?

What would happen if I build a half bath without permits?

Isn't the detector always measuring, and thus always collapsing the state?

Is the "spacetime" the same thing as the mathematical 4th dimension?

If someone asks a question using “quién”, how can one shortly respond?

Can you cure a Gorgon's Petrifying Breath before it finishes turning a target to stone?

How do we know neutrons have no charge?

Is there an in-universe explanation of how Frodo's arrival in Valinor was recorded in the Red Book?

Can an energy drink or chocolate before an exam be useful ? What sort of other edible goods be helpful?

How to add the real hostname in the beginning of Linux cli command

How does Monks' Improved Unarmored Movement work out of combat?

Avoiding dust scattering when you drill

How to work around players whose backstory goes against the story?

CouchDB Document modelling

MongoDB or CouchDB - fit for production?Principles for Modeling CouchDB DocumentsAggregating data with CouchDB reduce functionCouchDB - Basic design for joins dataCouchDB map/reduce by any document property at runtime?Using CouchDB and Redis together for transactional dataWhen to use CouchDB over MongoDB and vice versacouchDB: view that returns NOT NULL values, doesn't return NULL valuesWhy do CouchDB Reduce Functions have to be Commutative?Sum values in CouchDB documents

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

0

[TLDR] Does CouchDB cache and reuse the results of map/reduce functions for non-modified documents?

Background info:
In my Point of Sale (POS) application, all the transactions are logged and created separate document.

"_id": "sale_transactions_1234124", "Quanity Added": 0, "Quanity reduced": 10, "Is Discarded": "false", "saleid": "sales_523"

"_id": "Purchaseorder_transactions_1234124", "Quanity Added": 5, "Quanity reduced": 0, "Is Discarded": "false" , "purchaseid": "purchase_2352"

Whenever the inventory is modified, relevant documents are created as transactions it is _id field. So instead of store Total sold, Quantity in hand in Item document, have plan to create map reduce view to retrieve every time.

Every time when I make a sale, Quantity in hand map reduce function should be called, to check whether the quantity is greater than zero. For this approach will I encounter any performance issue, or did you recommend create Total sold, Quantity in hand in Item document

So every time we call map reduce function, is couchdb some how cache non-modified document results and process new and modified documents, or is it process all the documents in every time?

couchdb

share|improve this question

edited Apr 10 at 6:04

Nest

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Is your question simply: Does CouchDB cache and reuse the results of map/reduce functions for non-modified documents?
  
  – Flimzy
  Mar 29 at 7:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Yes. If it always cache, instead of storing values, is it good practice to rely map-reduce function.
  
  – Nest
  Mar 29 at 7:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You could just ask that question, without all the unnecessary background info :)
  
  – Flimzy
  Mar 29 at 7:36
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You are right. Shall I edit this question or ask new question?
  
  – Nest
  Mar 29 at 8:08
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I would just edit this one.
  
  – Flimzy
  Mar 29 at 8:10
  

  
  
  
  

 | 
show 3 more comments

0

[TLDR] Does CouchDB cache and reuse the results of map/reduce functions for non-modified documents?

Background info:
In my Point of Sale (POS) application, all the transactions are logged and created separate document.

"_id": "sale_transactions_1234124", "Quanity Added": 0, "Quanity reduced": 10, "Is Discarded": "false", "saleid": "sales_523"

"_id": "Purchaseorder_transactions_1234124", "Quanity Added": 5, "Quanity reduced": 0, "Is Discarded": "false" , "purchaseid": "purchase_2352"

Whenever the inventory is modified, relevant documents are created as transactions it is _id field. So instead of store Total sold, Quantity in hand in Item document, have plan to create map reduce view to retrieve every time.

Every time when I make a sale, Quantity in hand map reduce function should be called, to check whether the quantity is greater than zero. For this approach will I encounter any performance issue, or did you recommend create Total sold, Quantity in hand in Item document

So every time we call map reduce function, is couchdb some how cache non-modified document results and process new and modified documents, or is it process all the documents in every time?

couchdb

share|improve this question

edited Apr 10 at 6:04

Nest

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Is your question simply: Does CouchDB cache and reuse the results of map/reduce functions for non-modified documents?
  
  – Flimzy
  Mar 29 at 7:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Yes. If it always cache, instead of storing values, is it good practice to rely map-reduce function.
  
  – Nest
  Mar 29 at 7:34
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You could just ask that question, without all the unnecessary background info :)
  
  – Flimzy
  Mar 29 at 7:36
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  You are right. Shall I edit this question or ask new question?
  
  – Nest
  Mar 29 at 8:08
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I would just edit this one.
  
  – Flimzy
  Mar 29 at 8:10
  

  
  
  
  

 | 
show 3 more comments

[TLDR] Does CouchDB cache and reuse the results of map/reduce functions for non-modified documents?

Background info:
In my Point of Sale (POS) application, all the transactions are logged and created separate document.

"_id": "sale_transactions_1234124", "Quanity Added": 0, "Quanity reduced": 10, "Is Discarded": "false", "saleid": "sales_523"

"_id": "Purchaseorder_transactions_1234124", "Quanity Added": 5, "Quanity reduced": 0, "Is Discarded": "false" , "purchaseid": "purchase_2352"

Whenever the inventory is modified, relevant documents are created as transactions it is _id field. So instead of store Total sold, Quantity in hand in Item document, have plan to create map reduce view to retrieve every time.

Every time when I make a sale, Quantity in hand map reduce function should be called, to check whether the quantity is greater than zero. For this approach will I encounter any performance issue, or did you recommend create Total sold, Quantity in hand in Item document

So every time we call map reduce function, is couchdb some how cache non-modified document results and process new and modified documents, or is it process all the documents in every time?

couchdb

share|improve this question

edited Apr 10 at 6:04

Nest

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

share|improve this question

edited Apr 10 at 6:04

Nest

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

share|improve this question

edited Apr 10 at 6:04

Nest

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

asked Mar 28 at 20:07

NestNest

8822 silver badges1717 bronze badges

1 Answer
1

active

oldest

votes

0

Yes CouchdDB caches your map/reduce documents. So if you query the same view multiple times Couch will give you the cached version. If additional datasets are added to the database Couch will update the view.

To see that Couch caches the views you can try to create a new view on a database with a lot of documents:

1. Call the view for the first time and you will see that it takes some time to get your result.


2. Call your view again and it will be ready immediately.


3. Add a few new documents to your database


4. Call your view and it will be ready very fast if not immediately.


5. Add a lot of new documents to your database


6. Call your view again and it will take more time than when you just added a few new documents. But will be ready immediately after it is build up.

share|improve this answer

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

add a comment
 | 

Your Answer

StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/4.0/"u003ecc by-sa 4.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55406041%2fcouchdb-document-modelling%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

0

Yes CouchdDB caches your map/reduce documents. So if you query the same view multiple times Couch will give you the cached version. If additional datasets are added to the database Couch will update the view.

To see that Couch caches the views you can try to create a new view on a database with a lot of documents:

1. Call the view for the first time and you will see that it takes some time to get your result.


2. Call your view again and it will be ready immediately.


3. Add a few new documents to your database


4. Call your view and it will be ready very fast if not immediately.


5. Add a lot of new documents to your database


6. Call your view again and it will take more time than when you just added a few new documents. But will be ready immediately after it is build up.

share|improve this answer

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

add a comment
 | 

0

Yes CouchdDB caches your map/reduce documents. So if you query the same view multiple times Couch will give you the cached version. If additional datasets are added to the database Couch will update the view.

To see that Couch caches the views you can try to create a new view on a database with a lot of documents:

1. Call the view for the first time and you will see that it takes some time to get your result.


2. Call your view again and it will be ready immediately.


3. Add a few new documents to your database


4. Call your view and it will be ready very fast if not immediately.


5. Add a lot of new documents to your database


6. Call your view again and it will take more time than when you just added a few new documents. But will be ready immediately after it is build up.

share|improve this answer

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

add a comment
 | 

Yes CouchdDB caches your map/reduce documents. So if you query the same view multiple times Couch will give you the cached version. If additional datasets are added to the database Couch will update the view.

To see that Couch caches the views you can try to create a new view on a database with a lot of documents:

1. Call the view for the first time and you will see that it takes some time to get your result.


2. Call your view again and it will be ready immediately.


3. Add a few new documents to your database


4. Call your view and it will be ready very fast if not immediately.


5. Add a lot of new documents to your database


6. Call your view again and it will take more time than when you just added a few new documents. But will be ready immediately after it is build up.

share|improve this answer

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

share|improve this answer

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges

answered Apr 11 at 10:52

Jay BeeJay Bee

7611 silver badge77 bronze badges