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Curated SQL Posts

Oracle Error ORA-28353: Failed to Open Wallet

Published 2020-10-09 by Kevin Feasel

Rene Antunez diagnoses an Oracle error:

I noticed the original error after applying the October 2018 bundle patch (BP) for 11.2.0.4. While I realize most clients are no longer in 11.2.0.4, this information remains valid for anyone upgrading from 11.2 to 12, 18 or 19c.

I had been doing several tests on my Spanish RAC (Real Application Cluster) Attack for 12.2. The goal was to patch my client to October 2018 PSU; obtaining enough security leverage to avoid patching their database and do their DB (database) upgrade to 18c. I created RAC VMs to enable testing. I also set up my environment to match the client’s, which had TDE with FIPS 140 enabled (I will provide more details on this later in the post).

While the patching was successful, the problem arose after applying the patch. I was unable to open the database despite having the correct password for the encryption key.

When I first read the title, I thought it was a joke making fun of Oracle’s licensing practices.

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Tips for Moving to a Multi-Tenant Setup

Published 2020-10-09 by Kevin Feasel

Adrian Hills continues a series on multi-tenant SQL Server:

What you knew a few years ago might differ significantly from the reality today, whether you started off with a single tenant system that you pivoted quickly to support multiple tenants, or you envisioned 10s of tenants and ended up with 1000s. Whatever that reality is, when you experience pain points around the 3 considerations I covered in part 1 of this series (security, maintainability, and scalability), it can lead to a need to change the multi-tenancy approach you’re using. Often, the biggest driver for change is around performance and scalability and typically tends to be related to a need to move from a less-isolated multi-tenancy approach (single database) to a more-isolated approach that supports the scaling out of workloads (multiple databases).

In the steps below, I’ll cover the general path you can follow to successfully make an architectural change like this to the database layer. As a provider of database performance monitoring and DataOps tools, SentryOne offers some tools that can come in handy along the way, so I’ll call those out as we go.

Click through for guidance.

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SSIS Code Promotion

Published 2020-10-09 by Kevin Feasel

Andy Leonard takes us through the process of migrating code from development through to production:

Developers need to able to develop software that will execute enterprise operations.
Production is solely managed by operations personnel. Allow very little, if any, developer access to Production.
Before deploying to Production, operations personnel need a Pre-Production environment they can use to test the deployment and performance after the deployment. No one wants operations personnel – or anyone, really – deploying a process to Production without a practice run.
Similarly, developers need to move their code from the Development tier (aka the “works on my machine” tier) to another tier – such as Test – so they can identify hard-coded defaults that should be parameters.

Read on for some tips from Andy, including where the SSIS Catalog Compare product can fit into this.

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With Query Store, Alter instead of Drop and Create

Published 2020-10-09 by Kevin Feasel

Erin Stellato has a recommendation when running Query Store:

When I talk about Plan Forcing I always discuss how users should ALTER procedures when using Query Store, and not use DROP and CREATE. This is valid beyond Plan Forcing cases; it’s a best practice I recommend however you are using Query Store. Every query stored in Query Store has an object_id associated with it, which ties it back to its object (stored procedure, function, etc.). This is critical not just for plan forcing, but also when you want to look at historical performance for a query after a change to the object.

Read on for a demonstration of why this is important.

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Projecting Defensive Back Trajectories with Sagemaker

Published 2020-10-08 by Kevin Feasel

Lin Lee Cheong, et al, relay some interesting research:

NFL’s Next Gen Stats (NGS) powered by AWS accurately captures player and ball data in real time for every play and every NFL game—over 300 million data points per season—through the extensive use of sensors in players’ pads and the ball. With this rich set of tracking data, NGS uses AWS machine learning (ML) technology to uncover deeper insights and develop a better understanding of various aspects and trends of the game. To date, NGS metrics have focused on helping fans better appreciate and understand the offense and defense in gameplay through the application of advanced analytics, particularly in the passing game. Thanks to tracking data, it’s possible to quantify the difficulty of passes, model expected yards after catch, and determine the value of various play outcomes. A logical next step with this analytical information is to evaluate quarterback decision-making, such as whether the quarterback has considered all eligible receivers and evaluated tradeoffs accurately.

To effectively model quarterback decision-making, we considered a few key metrics—mainly the probability of different events occurring on a pass, and the value of said events. A pass can result in three outcomes: completion, incompletion, or interception. NGS has already created models that provide probabilities of these outcomes, but these events rely on information that’s available at only two points during the play: when the ball is thrown (termed as pass-forward), and when the ball arrives to a receiver (pass-arrived). Because of this, creating accurate probabilities requires modeling the trajectory of players between those two points in time.

For these probabilities, the quarterback’s decision is heavily influenced by the quality of defensive coverage on various receivers, because a receiver with a closely covered defender has a lower likelihood of pass completion compared to a receiver who is wide open due to blown coverage. Furthermore, defenders are inherently reactive to how the play progresses. Defenses move in completely different ways depending on which receiver is targeted on the pass. This means that a trajectory model for defenders has to similarly be reactive to the specified targeted receiver in a believable manner.

Click through for details on the study.

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Building a CRUD Application with Cloudera Operational DB and Flask

Published 2020-10-08 by Kevin Feasel

Shlomi Tubul puts together a proof of concept app:

In this blog, I will demonstrate how COD can easily be used as a backend system to store data and images for a simple web application. To build this application, we will be using Phoenix, one of the underlying components of COD, along with Flask. For storing images, we will be using an HBase (Apache Phoenix backend storage) capability called MOB (medium objects). MOB allows us to read/write values from 100k-10MB quickly. 

*For development ease of use, you can also use the Phoenix query server instead of COD. The query server is a small build of phoenix that is meant for development purposes only, and data is deleted in each build. 

Click through for the demo and for a link to the GitHub repo.

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Read Those Error Messages

Published 2020-10-08 by Kevin Feasel

Randolph West has a public service announcement:

My boss got upset with us one day on The Project From Hell. Tempers were frayed, tensions ran high, and other euphemisms were euphemisming. In short, we were all grumpy, and as expected on a project of this nature we kept making obvious mistakes and wasting our energy chasing our tails.

Obvious? Well, yes. It turns out that the answer to a particularly common issue we were running into was explained in the first line of the stack trace of the code that kept crashing. I’m not exaggerating for the sake of this story. The actual problem was explained in the first sentence of the error, in the very first line.

Microsoft products are fairly notorious about poorly-crafted error messages, but as Randolph mentions, often the solution is there if you take care to read the message.

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Diving Into the Window Spool Operator

Published 2020-10-08 by Kevin Feasel

Hugo Kornelis continues a series on execution plan operators:

The Window Spool operator is one of the four spool operators that SQL Server supports. Like other spool operators, it retains a copy of data it receives and can then return those rows as often as needed. The specific functionality of the Window Spool operator allows it to replay rows within a window, as defined in a ROWS or RANGE specification of an OVER clause.

Read on to see how these work, as well as a few differences from their spool brethren.

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Exporting Environment Variables from the SSIS Catalog

Published 2020-10-08 by Kevin Feasel

Koen Verbeeck shows how we can pull environment variables out from the SSIS catalog:

Sometimes when you’ve created a SSIS catalog, along with folders, environments and environment variables, you want this content on another server. Unfortunately, you can only script out these objects in SSMS at the moment you’re creating them (thus right before you clikc ‘OK’ to confirm). Once the objects are created, you can no longer script them out using the GUI.

Luckily, there’s a whole slew of stored procedures and views in the catalog that allow us to extract information and use that information to re-create the objects. Here are two scripts that I found useful.

Click through for the scripts.

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Clone Logins and Users with dbatools

Published 2020-10-08 by Kevin Feasel

Jana Sattainathan takes us through a couple of DBA scenarios:

One of the more frequent requests that a SQL Server DBA receives is to “Clone a login” with all its permissions. For example a request could be

– Clone BILL_BLACK’s login and create a new login JACK_JOHNSON with exactly the same privileges in all databases.
– Clone AD group login BILLING_APP_ADMINS and create a login for new AD group BILLING_APP_CONSULTANTS with the same permissions as BILLING_APP_ADMINS in all databases

Read on to see how.

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