Errata

Tod Hanseman should be spelled Tod Hansmann

Lior Gavish is mentioned twice

Note from the Author or Editor:
Please remove the second reference to Lior Gavish in acknowlegements

The line
"That's it! Now let’s look at ways to view data contextually using satellites.'
does not seem to fit in this place

The line should be just below the table 8-18, and above the 'Satelites' paragraph.

Note from the Author or Editor:
This might read better if we move the "That's it! Now let’s look at ways to view data contextually using satellites.' sentence to the end of the Link section, after the sentence that says "Note that we're...". This is the sentence right before the satellite portion begins.

Figure 2-7 under DataOps, the first item should be Automation, not Data Governance.
This would bring figure 2-7 in line with the items in figure 2-8.

Note from the Author or Editor:
Replace "Data Governance" with "Automation" in the diagram.

"...which we discuss at greater length in 'Messages and Streams' on page 167.)" should probably read, "...which we discuss at greater length in 'Message Queues and Event-Streaming Platforms' on page 259.)". In its current form, this is a self-referential breadcrumb, and the preceding paragraphs in the section do not "discuss at greater length," whereas the aforementioned section starting on page 259 does go into more detail. This is a particularly confusing typo due to the section name. Indeed, I did not understand the parenthetical until 100 pages later!

Note from the Author or Editor:
O'Reilly - can we fix this? Thanks.

"Understand how to leverage for efficient extraction." Feels like it should read "Understand how to leverage them for efficient extraction." or "Understand how to leverage indexes for efficient extraction."

Note from the Author or Editor:
Fixed in Atlas branch mlhousley

"from routing messages between microservices ingesting millions of events per second of event data from web, mobile, and IoT applications." This feels like there should be to "to" somewhere in this sentence

Note from the Author or Editor:
Fixed in Atlas on branch mlhousley.

The last sentence of the paragraph reads, "A topic can have zero, one, or multiple producers and customers on most event-streaming platforms."

It should probably read, "A topic can have zero, one, or multiple producers and consumers on most event-streaming platforms."

So, "consumers", not "customers ".

Note from the Author or Editor:
Confirmed. Please correct.

"...-should extend up and down the entire stack and support the data engineering and lifecycle."

Not sure the last and is supposed to be there?

Note from the Author or Editor:
Delete the last "and"

In the first paragraph there is a reference to a figure that reads (see Figure 6-3).

It should reference Figure 6-2.

Note from the Author or Editor:
Confirmed

"The storage price goes down from faster/higher performing storage to lower storage"

Shouldn't this be:

"The storage price goes down from faster/higher performing storage to slower storage"

"Make sure the code you write stores the data correctly and doesn't accidentally cause data, memory leaks, or performance issues."

What is meant by "...cause data"?

Note from the Author or Editor:
Edit: "Make sure that your code stores the data correctly and doesn't accidentally cause memory leaks or performance issues."

"The big idea is that rather than relying on asynchronous processing, where a batch process runs for each stage as the input batch closes and certain time conditions are met, each stage of the asynchronous pipeline can process data items as they become available in parallel across the Beam cluster"

Shouldn't the first "asynchronous" be "synchronous" ?

"The key-value pairs and nesting depth occur with subelements"

Is the word "occur" needed? Unsure of the meaning with it in there.

Note from the Author or Editor:
"The key-value pairs and nesting structure"

"Schema is not only for databases. As we've discussed, present their schema complications"

Shouldn't this read as follows?:

"Schema is not only for databases. As we've discussed, present their own schema complications"

Note from the Author or Editor:
Text should read "As we've discussed, APIs present..."

"Some size-based ingestion systems can break data into objects based on various criteria, such as the size in bytes of the total number of events."

Shouldn't this be

"Some size-based ingestion systems can break data into objects based on various criteria, such as the size in bytes or the total number of events."

"Find the right balance of TTL impact on our data pipeline."

Shouldn't it read

"Find the right balance of TTL impact on your data pipeline."

"In that case, your data sizes are presumably batching or streaming much smaller data sizes on an ongoing basis."

Should this be re-written? Feels awkward. Maybe:

"In that case, you are presumably batching or streaming much smaller data sizes on an ongoing basis."

or

"In that case, your data sizes are presumably at a batching or streaming scale on an ongoing basis."

Note from the Author or Editor:
Yes, the first suggestion is correct, thank you!

"Involving product managers in the outcome and treating downstream data processed as part of a product encourages them to allocate scarce software development to collaboration with data engineers."

Shouldn't this be "software development time" or "software development resources?"

Note from the Author or Editor:
change from "scare software development" to "software development resources"

"The last thing you want is to capture or compromise the data while moving."

Shouldn't this be:

"The last thing you want is for the data to be captured or compromised while moving."

"This means that engineers develop and test code on simulated or cleansed data in development and staging environments but automated code deployments to production."

Shouldn't this be "automate" instead of "automated"?

"An orchestration can start each ingestion task at the appropriate scheduled time..."

Unsure if this is actually a typo or not but feels like it should read:

"An orchestrator can start each ingestion task at the appropriate scheduled time..."

Page 287 "if new events arrive for the use" should be user

"Along this continuum (Figure 8-12), three main data models are conceptual, logical, and physical."

Shouldn't that be a "the" or "the three"?

Bundling a few together from this section.

1. "Using our ecommerce scenario, let's look at an example of a hub for products. First, let's look at the physical design of a product hub."

Either these are two redundant sentences, or this should read more like:

"Using our ecommerce scenario, let's look at an example of a data vault model for products. First, let's look at the physical design of a product hub."

2. All unpopulated examples show each column of a data vault table as a row, and then when populated, they are all columns. Table names are referenced in empty table examples but not populated ones.

I think examples similar to the normalization section table examples might make more sense. So, getting rid of empty table examples and changing table text more like: "Table 8-15. ProductHub"

But that's just one idea and this suggestion may be nitpicky on my part.

At the end of the Links paragraph on 307, you say "That's it! Now let's look at ways to view data contextually using satellites."

However, the very next paragraph you go into an example of a link table.

Note from the Author or Editor:
1. "First, let's look at the physical design."

2. We'll have to leave this as-is for now, but will keep in mind for future.

3. Fixed per another errata item

"However, these aren't committed to a Git repository without an external CI/CD system to manage deployment."

Shouldn't this be:

"However, these aren't committed to a Git repository with an external CI/CD system to manage deployment."

Note from the Author or Editor:
Revised for clarity:
"However, UDFs aren’t automatically committed to a Git repository unless you've set up CI/CD processes to manage deployment."

"A complex query that filters with a WHERE clause joins three tables and applies a window function that would consist of many map and reduce stages."

Shouldn't this read:

"A complex query that filters with a WHERE clause, joins three tables and applies a window function would consist of many map and reduce stages."

Note from the Author or Editor:
Yes, thank you!

"Let's take a simple example where streaming DAG would be useful."

Shouldn't this be: "Let's take a simple example where a streaming DAG would be useful."

"If someone does have access to a dataset, continue to control who has access to a dataset's column, row, and cell-level access."

Not sure what is meant by this sentence but it feels a bit clunky. Possible alternatives based on my best guess of the intended meaning:

1. "If someone does have access to a dataset, you can further refine that access at the column, row, and cell level."

2. "If someone does have access to a dataset, you can further refine that access at the column, row, and cell level, according to the principle of least privilege."

3. "Access can be granted broadly for an entire dataset, or narrowed to specific columns, rows, or cells on a case by case basis."

Note from the Author or Editor:
Let's use your first suggestion, but with "cell" changed to "field"

"...- the latter two are popular for data science applications, especially notebooks."

Is this supposed to be?:

"...- the latter two are popular for data science applications, especially in notebooks."

Unsure what is meant by "roll" in:

"While you can roll your reverse ETL solution, many off-the-shelf reverse ETL options are available."

Should that have been "roll out", or "build your own" ?

Note from the Author or Editor:
Should be "roll your own"

"We're amazed at the number of companies with security policies in the hundreds of pages that nobody reads, the annual security policy review that people immediately forget, all in checking a box for a security audit."

I feel like this should be:

"We're amazed at the number of companies with security policies in the hundreds of pages that nobody reads, and annual security policy reviews that people immediately forget, all in the name of checking a box for a security audit."

or

"We're amazed at the number of companies with security policies in the hundreds of pages that nobody reads, and annual security policy reviews that people immediately forget, all in the name of checking a box or fear of a security audit."

Note from the Author or Editor:
First suggestion is good, thanks!

"...give them only the privileges and data they need to do their jobs, and only for the timespan when needed."

Should be

"...give them only the privileges and data they need to do their jobs, and only for the timespan they're needed."

or

"...give them only the privileges and data they need to do their jobs when needed, and only for the timespan they're needed."

Note from the Author or Editor:
"give them only the privileges and data they need to do their jobs, and only for the necessary timespan"

"Arrow has already spanned a new data warehouse product;"

Shouldn't this be

"Arrow has already spawned a new data warehouse product;"

"Cloud providers offer CDN options and many other providers, such as Cloudflare."

Was this meant to be:

"Cloud providers and many other providers, such as Cloudflare offer CDN options."