storage

问题 I am using Python and I have a JSON file in which I would like to update a value related to a given key. That is, I have the my_file.json containing the following data {"a": "1", "b": "2", "c": "3"} and I would like to just change the value related to the b key from 2 to 9 so that the updated file look as like: {"a": "1", "b": "9", "c": "3"} How can I make that? I tried the following but without success (the changes are not saved to the file): with open('my_file.json', 'r+') as f: json_data =

问题 I am building a site that is looking at Millions of photos being uploaded easily (with 3 thumbnails each for each image uploaded) and I need to find the best method for storing all these images. I've searched and found examples of images stored as hashes.... for example... If I upload, coolparty.jpg, my script would convert it to an Md5 hash resulting in.. dcehwd8y4fcf42wduasdha.jpg and that's stored in /dc/eh/wd/dcehwd8y4fcf42wduasdha.jpg but for the 3 thumbnails I don't know how to store

问题 I am building a site that is looking at Millions of photos being uploaded easily (with 3 thumbnails each for each image uploaded) and I need to find the best method for storing all these images. I've searched and found examples of images stored as hashes.... for example... If I upload, coolparty.jpg, my script would convert it to an Md5 hash resulting in.. dcehwd8y4fcf42wduasdha.jpg and that's stored in /dc/eh/wd/dcehwd8y4fcf42wduasdha.jpg but for the 3 thumbnails I don't know how to store

问题 What is the key difference between IOPS and Throughput in large data storage? Does file size have an effect on IOPS? Why? 回答1: IOPS measures the number of read and write operations per second, while throughput measures the number of bits read or written per second. Although they measure different things, they generally follow each other as IO operations have about the same size. If you have large files, you simply need more IO operations to read the entire file. The file size has no effect on

问题 I am looking for a reasonably well tested library+server to store a persistent distributed hash table. I am hesistant to use SQL-based solutions as the data is highly document oriented, consisting of millions of ~64KB blobs with only a single index (computed by hash of said BLOB) - and needs to be able to be distributed for long term scaling prospects. Due to expense and bandwidth considerations, external solutions such as S3 are not an option. Something like CouchDB or Project Voldemort

问题 I'm kinda new in Prolog and I'm using SWI-Prolog v6.6 to storage asserts in my *.pl file. :- dynamic fact/2. assert(fact(fact1,fact2)). With the code above I can make asserts and it works fine, but the problem is when I close SWI-Prolog and I open the *.pl file again, the asserts i've made are gone... There is a way to make asserts and those get stored even if I close the SWI-Prolog? Sorry about my bad english and Thanks! (: 回答1: Saving state has certain limitations, also see the recent

问题 I want to limit the number of files that a user can upload to a firebase storage path. Here is my firebase storage rule: service firebase.storage { match /b/jobsdbn.appspot.com/o { match /images/Business/{userId}/{imageId} { allow read allow write: if request.auth.uid == userId && (request.resource == null || ( (list(/images/Business/$(username)).size() <= 5) && imageId.size() < 50 && request.resource.size < 10 * 1024 * 1024 && request.resource.contentType.matches('image/.*'))) } } } I have

问题 The following is what I use to get the available storage space on an iOS device for my app: NSDictionary *dict = [[NSFileManager defaultManager] fileSystemAttributesAtPath:@"/var"]; NSNumber *freeSpace = [dict valueForKey:@"NSFileSystemFreeSize"]; However, the value freeSpace does not correspond with the one shown in the Settings app. The value is always greater than the value shown by Settings. For example, freeSpace is approximately 600,000,000 bytes, where Settings shows 357 MB. Why is

问题 In SQL Server you can use FLOAT or REAL to store floating point values the storage format of which is cleared defined by the IEEE 754 standard. For fixed point values we can use DECIMAL type (which has a synonym NUMERIC ). However I'm not pretty sure how SQL Server store DECIMAL values internally. For example, if I define a table and insert a row like this: IF OBJECT_ID('dbo.test_number_types') IS NOT NULL DROP TABLE dbo.test_number_types; CREATE TABLE dbo.test_number_types ( id INT IDENTITY

问题 I'm using PostgreSQL 9.2 on Oracle Linux Server release 6.3. According to the storage layout documentation, a page layout holds: PageHeaderData(24 byte) n number of points to item(index item / table item) AKA ItemIdData(4 byte) free space n number of items special space I tested it to make some formula to estimate table size anticipated...(TOAST concept might be ignored.) postgres=# \d t1; Table "public.t1" Column ',' Type ',' Modifiers ---------------+------------------------+---------------