merkel | Handles your database migration crisis | Data Migration library
kandi X-RAY | merkel Summary
kandi X-RAY | merkel Summary
Handles your database migration crisis. merkel is a framework-agnostic database migration tool designed to autonomously run in Continuous Deployment, with rollbacks in mind.
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of merkel
merkel Key Features
merkel Examples and Code Snippets
Community Discussions
Trending Discussions on merkel
QUESTION
I tried to simplify some expressions I created in Jupyter lab. Sorry for my bad written text, this is my first post here, so I am very new.
This is the original code and it is working:
...ANSWER
Answered 2021-Apr-30 at 03:09I think in this case you can use a dictionary (pddict) instead of a list to store the dataframes so that you can associate the prefixes (all, de, en) with their dataframes (df = pddict[key]). With the dictionary pddict, you can iterate through each key and derive the key values (all_merkel, en_merkel, etc.) by appending the key with _merkel. Let me know if encounter any issues
QUESTION
I know there are a lot of similar questions out there but I haven't found any that matches my scenario exactly so please don't be too trigger-happy with the Duplicate flag. I'm working in a Python 3 notebook in Azure Databricks with Spark 3.0.1.
I have the following DataFrame
...ANSWER
Answered 2021-Mar-16 at 18:24You can use the higher-order function filter:
QUESTION
Attempt
After reading a large json file and capturing only the 'text' column, I would like to add a column to dataframe and set all rows to a specific value:
ANSWER
Answered 2021-Feb-19 at 04:23The problem is that your read_json(....).text line returns a series, not a dataframe.
Adding a .to_frame() and referencing the column in the following line should fix it:
QUESTION
I am rewriting old legacy system written in PHP/HTML into Java/SpringBoot/Thymeleaf. In the old system, there is table displaying search result. In the column "Sentence" I call this function in order to highlight search keywords inside the sentence string.
...ANSWER
Answered 2020-Dec-21 at 12:10I tried out your case and it works fine for me in both Chrome and Firefox. I think we need to elaborate your CSS. If the mark is indeed added to the html content of the td then something is going on with your CSS. You may have a look in the developer tools of your browser. (Usually invoked via F12) Find the misbehaving mark in your td and Elaborate the Style-Sheet attributes that actually are applied. Maybe some !important attribute elsewhere in the code overrides your settings.
QUESTION
I'm trying to perform an action over a 4-dimensional array. This array ends up being incredibly big, but is necessary for the data that i'm processing. Now the process itself goes swell, but i want to make it ready for parallel computing. I've got access to a 96-core mainframe and i want to use it.
So far i've read online that the easiest way to get this done is by using mclapply(), the parallelized version of lapply(). I know the basics of how lapply() works, but i can't quite figure out how to apply it in this situation.
I have a 4-dimensional array that's filled with NAs. Each dimension has dimnames. I want to compare the dimnames of dimension 1 with dimension 3 and dimension 2 with dimension 4 (this is done by a custom function that i wrote). If they all match up, a number comes out and i want that number to be entered into xy[i, k, j, l] where the letters i-l represent the indices for one entry.
In the example below i have simplified it into an addition of the nchar() values for the dimnames.
...ANSWER
Answered 2020-Oct-14 at 16:18fun_on_names <- function(Var1, Var2, Var3, Var4){
a <- nchar(Var1) + nchar(Var3)
b <- nchar(Var2) + nchar(Var4)
if(!is.null(a) & !is.null(b)) return(a + b)
else return(NA)
}
xy[] <- do.call(parallel::mcmapply,
c(list(FUN = fun_on_names, mc.cores = 96),
expand.grid(dimnames(xy), stringsAsFactors = FALSE)))
QUESTION
i have a fetch that shows the below results. Now i want to show the fetch in the return statement(in the div results). Has anyone an idea how to do that. I tried it with a map function because i though the fetch is an array, but i failed.
...ANSWER
Answered 2020-Jun-04 at 11:18QUESTION
I have two almost identical Pyspark dataframes: same number of rows and row_id, same schema, but different values on some of columns for each row.
I want to identify what are those columns for each row.
Example:
Dataframe A
...ANSWER
Answered 2020-Apr-10 at 06:53Here is a more generalized answer, using RDD conversion:
QUESTION
I have JSON output from m3inference package in python like this:
...ANSWER
Answered 2020-Mar-11 at 09:09"i dont know where 0 value in first column coming from then i save org.isorg column to isorg"
That "0" is an index to your dataframe. Unless you specify your dataframe index, pandas will auto create the index. You can change you index instead.
code example:
QUESTION
Context: I am trying to implement Amazon Dynamo's Replica Synchronisation which uses Merkel Trees to detect divergence amongst replicas.
As mentioned in the web version of the paper here,
Dynamo uses Merkle trees for anti-entropy as follows: Each node maintains a separate Merkle tree for each key range (the set of keys covered by a virtual node) it hosts. This allows nodes to compare whether the keys within a key range are up-to-date. In this scheme, two nodes exchange the root of the Merkle tree corresponding to the key ranges that they host in common. Subsequently, using the tree traversal scheme described above the nodes determine if they have any differences and perform the appropriate synchronization action.
I do not understand what is meant by "the appropriate synchronisation action". By using the appropriate traversal, assume we found a discrepancy between two Merkel tree's root node - how would we know which one is the correct one? Do we always take the more updated one according to its logical clock time stamp?
...ANSWER
Answered 2020-Feb-27 at 10:20The Dynamo paper which you linked (note that this is not the same as today's DynamoDB product, so I removed the dynamodb tag which you added on your question), explains how the reconciliation between two versions is done, using vector clocks (which aren't as simple as a "time stamp"):
Dynamo uses vector clocks in order to capture causality between different versions of the same object. A vector clock is effectively a list of (node, counter) pairs. One vector clock is associated with every version of every object. One can determine whether two versions of an object are on parallel branches or have a causal ordering, by examine their vector clocks. If the counters on the first object’s clock are less-than-or-equal to all of the nodes in the second clock, then the first is an ancestor of the second and can be forgotten. Otherwise, the two changes are considered to be in conflict and require reconciliation.
In other words, usually Dynamo can tell which value is the newer one based on the vector clocks (the paper explain what this means in detail), but it is also possible that there is a conflict - imagine that the same item was read and modified concurrently, and differently, by two different and uncommunicating replicas. In this case, both versions of the data will be saved in the database and returned to the client, and the client will need to reconcile them using some client-specific logic. For example, in Amazon's shopping cart example, if one modification was to add product A to the shopping cart, and a second modification was to add product B to the shopping cart, the reconciliation would be to add both products - A and B - to the shopping cart.
QUESTION
I made a multiple choice game and tried to randomize the questions by using the shuffle method on my array which contains all my questions. The problem is that some questions are being constantly repeated, so you will see some questions two times, some you won't see at all. I thought that I could use a arraylist instead of an array, so I could use the remove method after a question has been asked, but I Always get Errors with the arraylist and I don't even know if my approach makes sense. You can see my problem under that big chunk full of objects, in the ShuffleQuestions method and the ShowNextQuestion method.
How would you go on about this problem? Thank you for your help!
Here's my Code:
...ANSWER
Answered 2020-Feb-02 at 21:34You shuffle the question every time; that's the wrong way to go about it.
Shuffle ONCE only, then maintain a pointer into the structure; it starts at 0 and everytime you render a question, up it. This way, you walk through the entire array of questions precisely once, hitting every question exactly once, and the one-time sorting ensures that it'll be a uniform different order every time you go through.
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install merkel
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page
