problem description There are two indexes in mongo, the first is a single-field index of the {_ id} field, and the second index is a composite index composed of {chat_id, _ id}. When I use the query db.collection.find ({ "chat_id ": ObjectId ( "* ")...
raceback (most recent call last): File " home shenjianlin .local lib python3.4 site-packages twisted internet defer.py", line 653, in _runCallbacks current.result = callback(current.result, *args, **kw) File " home shenjianlin my_pr...
in java, mongodb is operated by multiple threads. uses mongoTemplate as an operation. then, there are more than five hundred threads to operate on the mongodb. then, it was found that none of the 500-plus threads had to create a new mongodb connection...
how can I delete the files under the journal file of mongodb? produced a lot of tables before, so some were deleted, but this folder still has more than 60 gigabytes, which is much larger than the size of the existing tables. how to clean it up? ...
case: a table has at least 30 million pieces of data per day. There are thousands of types. Can you now quickly read the maximum values of the day for thousands of types at a time, that is, the last record time of the day? Maybe 15:00. Maybe 23:00. I m...
I currently have a query using mongodb3.4, that needs to be paged. Paging needs to return the total number and number of pages. but that s the problem. Paging queries are fast, but counting is slow . The count statement is as follows: db.message.fin...
from serial import Serial from serial.tools.list_ports import comports from websocket_server import WebsocketServer @route( ) def index(info= ): return template( index.html , sers=[(desc, port) for port, desc, hwid in comports()], ...
error when installing vue-cli3 is as follows but can install vue-cli after installing vue-cli version shows 2.9.6 ask for help ...
is there such an api? can only be opened by clicking the button button? ...
I wanted to encapsulate a table component with search function myself, so I created a subcomponent tableWithSearch < template > {{tableData}} <!-- a.--> <div> <table :column="tableColumn" :data="tableDataAfterSearch...
as mentioned in the question, debug the mobile phone screen with Synchronize on PC by using the method of "android phone + Chrome for real machine debugging ". The aim is to solve unique problems on mobile phones. after use, on the PC side, the chang...