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How do I calculate tables size in Oracle
...table. Often you are interested to know "How much spaces the the Purchase Order table take, including any indexes" rather than just the table itself. You can always delve into the details. Note that this requires access to the DBA_* views.
COLUMN TABLE_NAME FORMAT A32
COLUMN OBJECT_NAME FORMAT A...
The type 'string' must be a non-nullable type in order to use it as parameter T in the generic type
Why do I get Error "The type 'string' must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method 'System.Nullable'"?
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How can building a heap be O(n) time complexity?
... useful; for example, when retrieving items with integer keys in ascending order or strings in alphabetical order. The principles are exactly the same; simply switch the sort order.
The heap property specifies that each node in a binary heap must be at least as large as both of its children. In part...
Reusable library to get human readable version of file size?
...came up with a version that avoids loops, using log2 to determine the size order which doubles as a shift and an index into the suffix list:
from math import log2
_suffixes = ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']
def file_size(size):
# determine binary order in ste...
What does functools.wraps do?
...@wim: I've written some decorators which do their own version of @wraps in order to perform various types of modification or annotation on the values copied over. Fundamentally, it's an extension of the Python philosophy that explicit is better than implicit and special cases aren't special enough t...
Why should I use a pointer rather than the object itself?
...y, you shouldn't abuse it. So here are some disadvantages in no particular order:
It is error-prone. Manual memory allocation is dangerous and you are prone to leaks. If you are not proficient at using the debugger or valgrind (a memory leak tool), you may pull your hair out of your head. Luckily ...
How do you serialize a model instance in Django?
...h trying to serialize a single object, not a list of objects. That way, in order to get rid of different hacks, just use Django's model_to_dict (if I'm not mistaken, serializers.serialize() relies on it, too):
from django.forms.models import model_to_dict
# assuming obj is your model instance
dic...
When/Why to use Cascading in SQL Server?
...onship can involve an exclusive "is part of" description. For example, an OrderLine record is part of its parent order, and OrderLines will never be shared between multiple orders. If the Order were to vanish, the OrderLine should as well, and a line without an Order would be a problem.
The canonic...
Sort array of objects by single key with date value
...his ES6 one-liner might be of help. yourArr.sort((a, b) => a.yourNumericOrderingKey > b.yourNumericOrderingKey). In my case I had to sort based on an order key that was coming inside the objects of main array.
– keshavDulal
Sep 20 at 10:53
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Why is address zero used for the null pointer?
... code you will still continue to designate null-pointers by constant 0. In order to assign a null-pointer value to a given pointer, you will continue to use expressions like p = 0. It is the compiler's responsibility to realize what you want and translate it into the proper null-pointer value repres...