Is there a “the item before this item in the BTREE index” operator?









up vote
0
down vote

favorite












I need to update a record matching a secondary key where a certain timestamp field is the highest value under a certain other value. I have a composite BTREE index that covers the two relevant columns.



Is there an equivalent of Java's TreeMap.floorKey() to retrieve the corresponding value in a PostgreSQL index?



I tried Googling for a solution and found only convoluted work-arounds for what should be a very simple and specific operation.






postgresql







share|improve this question





















  • Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
    – eurotrash
    Nov 10 at 22:10














up vote
0
down vote

favorite












I need to update a record matching a secondary key where a certain timestamp field is the highest value under a certain other value. I have a composite BTREE index that covers the two relevant columns.



Is there an equivalent of Java's TreeMap.floorKey() to retrieve the corresponding value in a PostgreSQL index?



I tried Googling for a solution and found only convoluted work-arounds for what should be a very simple and specific operation.






postgresql







share|improve this question





















  • Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
    – eurotrash
    Nov 10 at 22:10












up vote
0
down vote

favorite









up vote
0
down vote

favorite











I need to update a record matching a secondary key where a certain timestamp field is the highest value under a certain other value. I have a composite BTREE index that covers the two relevant columns.



Is there an equivalent of Java's TreeMap.floorKey() to retrieve the corresponding value in a PostgreSQL index?



I tried Googling for a solution and found only convoluted work-arounds for what should be a very simple and specific operation.






postgresql







share|improve this question













I need to update a record matching a secondary key where a certain timestamp field is the highest value under a certain other value. I have a composite BTREE index that covers the two relevant columns.



Is there an equivalent of Java's TreeMap.floorKey() to retrieve the corresponding value in a PostgreSQL index?



I tried Googling for a solution and found only convoluted work-arounds for what should be a very simple and specific operation.






postgresql




postgresql






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 10 at 21:50









Alex R

4,03294796




4,03294796











  • Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
    – eurotrash
    Nov 10 at 22:10
















  • Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
    – eurotrash
    Nov 10 at 22:10















Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
– eurotrash
Nov 10 at 22:10




Maybe a combination of ORDER BY, LIMIT, and OFFSET. Otherwise post more details.
– eurotrash
Nov 10 at 22:10

















active

oldest

votes











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',
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/3.0/"u003ecc by-sa 3.0 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


















StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53243754%2fis-there-a-the-item-before-this-item-in-the-btree-index-operator%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes















 

draft saved


draft discarded















































 


draft saved


draft discarded














StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53243754%2fis-there-a-the-item-before-this-item-in-the-btree-index-operator%23new-answer', 'question_page');

);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







-

這個網誌中的熱門文章

Barbados

圖片
For other uses, see Barbados (disambiguation). Not to be confused with Barbuda. Coordinates: 13°10′N 59°33′W  /  13.167°N 59.550°W  / 13.167; -59.550 Barbados Flag Coat of arms Motto:  "Pride and Industry" Anthem:  In Plenty and In Time of Need Capital and largest city Bridgetown 13°06′N 59°37′W  /  13.100°N 59.617°W  / 13.100; -59.617 Official languages English Recognised regional languages Bajan Creole Ethnic groups (est. 2010 [1] ) 92.4% black 3.1% multiracial 2.7% white 1.3% East Indian 0.5% other/unspecified Religion 75.6% Christian 2.5% other 20.6% none 1.2% unspecified [1] Demonym(s) Barbadian Bajan (colloquial) Government Unitary parliamentary constitutional monarchy • Monarch Elizabeth II •  Governor-General Dame Sandra Mason • Prime Minister Mia Mottley Legislature Parliament • Upper house Senate • Lower house House of Assembly Independence • From the United Kingdom 30 November 1966 Area • Total 439 km 2 (169 sq mi) (183rd) • Water (%) Negligib
閱讀完整內容

How to read a connectionString WITH PROVIDER in .NET Core?

圖片
6 I added .AddJsonFile("Connections.json", optional: true, reloadOnChange: true) in public Startup(IHostingEnvironment env) Connections.json contains: "ConnectionStrings": "DefaultConnection": "Server=(localdb)\mssqllocaldb;Database=DATABASE;Trusted_Connection=True;MultipleActiveResultSets=true", "COR-W81-101": "Data Source=DATASOURCE;Initial Catalog=P61_CAFM_Basic;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "COR-W81-100": "Data Source=DATASOURCE;Initial Catalog=Post_PS;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "MSEDGEWIN10": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name="COR_Basic"", "server&qu
閱讀完整內容

Node.js Script on GitHub Pages or Amazon S3

圖片
0 I'm wondering if I can run a Node.js script in my Jekyll page from GitHub Pages or Amazon S3? I think it can't run on GitHub Pages since it doesn't support server side code. Not too sure. The code is below: var Airtable = require('airtable'); var base = new Airtable(apiKey: 'YOUR_API_KEY').base('appAnZVyYqusNPV5Q'); base('Invitee list').select( // Selecting the first 3 records in Complete list: maxRecords: 3, view: "Complete list" ).eachPage(function page(records, fetchNextPage) // This function (`page`) will get called for each page of records. records.forEach(function(record) console.log('Retrieved', record.get('Email')); ); // To fetch the next page of records, call `fetchNextPage`. // If there are more records, `page` will get called again. // If there are no more records, `done` will get called. fetchNextPage(); , function done(err) if (err) console.error(err); return; ); node.js
閱讀完整內容