The method you currently use now is called adjacency list model. Another model to store hierarchical data in a (relational) database is the nested set model. Its implementation in SQL databases is well known. Also see this article for the modified preorder tree traversal algorithm. A very simple method: you could store a path per … Read more
You can use sqlitedict which provides key-value interface to SQLite database. SQLite limits page says that theoretical maximum is 140 TB depending on page_size and max_page_count. However, default values for Python 3.5.2-2ubuntu0~16.04.4 (sqlite3 2.6.0), are page_size=1024 and max_page_count=1073741823. This gives ~1100 GB of maximal database size which fits your requirement. You can use the package … Read more
LMDB is the most memory-efficient database around http://symas.com/mdb/inmem/ and also proven to be the most reliable – completely crash-proof. http://wisdom.cs.wisc.edu/workshops/spring-14/talks/Thanu.pdf Of the ones you’ve mentioned, Tokyo Cabinet has documented corruption issues https://www.google.com/search?q=cfengine+tokyo+cabinet+corruption BerkeleyDB also has well-documented corruption issues, as does Bitcask. (And bitcask is an in-memory-only DB anyway, so useless for your 1MB RAM requirement.) … Read more
If you need to extract an element key based on an index, this function can be used: public string getCard(int random) { return Karta._dict.ElementAt(random).Key; } If you need to extract the Key where the element value is equal to the integer generated randomly, you can use the following function: public string getCard(int random) { return … Read more
If you only need the dictionary keys 1, 2, and 3 use: your_dict.keys(). If you only need the dictionary values -0.3246, -0.9185, and -3985 use: your_dict.values(). If you want both keys and values use: your_dict.items() which returns a list of tuples [(key1, value1), (key2, value2), …].
Use: var dict = []; // Create an empty array dict.push({ key: “keyName”, value: “the value” }); // Repeat this last part as needed to add more key/value pairs Basically, you’re creating an object literal with two properties (called key and value) and inserting it (using push()) into the array. This does not create a … Read more
When the syntax is bad for an otherwise decent pattern, change the syntax. How about: public void MyFunction(params KeyValuePair<string, object>[] pairs) { // … } public static class Pairing { public static KeyValuePair<string, object> Of(string key, object value) { return new KeyValuePair<string, object>(key, value); } } Usage: MyFunction(Pairing.Of(“Key1”, 5), Pairing.Of(“Key2”, someObject)); Even more interesting would … Read more
I assume by “key” and “value” you mean: <select> <option value=”KEY”>VALUE</option> </select> If that’s the case, this will get you the “VALUE”: $(this).find(‘option:selected’).text(); And you can get the “KEY” like this: $(this).find(‘option:selected’).val();
Let’s say you have a Dictionary called fooDictionary fooDictionary.Values.ToList().IndexOf(someValue); Values.ToList() converts your dictionary values into a List of someValue objects. IndexOf(someValue) searches your new List looking for the someValue object in question and returns the Index which would match the index of the Key/Value pair in the dictionary. This method does not care about the … Read more
Key-value, heirarchical, map-reduce, or graph database systems are much closer to implementation strategies, they are heavily tied to the physical representation. The primary reason to choose one of these is if there is a compelling performance argument and it fits your data processing strategy very closely. Beware, ad-hoc queries are usually not practical for these … Read more