CompTIA Updated DA0-001 Exam Questions and Answers by dalia

This is because First Name is a variable name format that would be problematic if used in most of the data software programs, such as Excel, SQL, or Python. This is because First Name contains a space between two words, which could cause confusion or errors in the data software programs, as they might interpret the space as a separator or a delimiter between two different variables or values, rather than as part of a single variable name. For example, in SQL, a space is used to separate keywords, clauses, or expressions in a statement, such as SELECT, FROM, WHERE, etc. Therefore, using First Name as a variable name in SQL could result in a syntax error or an unexpected result. The other variable name formats would not be problematic if used in most of the data software programs. Here is why:

First_Name_ is a variable name format that uses an underscore (_) to separate two words, which is a common and acceptable practice in most of the data software programs, as it helps to improve the readability and clarity of the variable name. For example, in Python, an underscore is used to follow the PEP 8 style guide for naming variables, which recommends using lowercase letters and underscores for multi-word variable names.

FirstName is a variable name format that uses camel case to separate two words, which is another common and acceptable practice in most of the data software programs, as it helps to reduce the length and complexity of the variable name. For example, in Excel, camel case is used to follow the VBA naming conventions for naming variables, which recommends using mixed case letters for multi-word variable names.

First_Name is a variable name format that also uses an underscore (_) to separate two words, which is also a common and acceptable practice in most of the data software programs, as it helps to improve the readability and clarity of the variable name. For example, in SQL, an underscore is used to follow the ANSI SQL naming standards for naming variables, which recommends using lowercase letters and underscores for multi-word variable names.

ETL is a process that is used during data integration to collect, blend, and load data. ETL stands for extract, transform, and load, which are the three main steps involved in moving data from different sources to a common destination, such as a data warehouse or a data lake. ETL helps to consolidate and standardize data for analysis and reporting purposes. References: CompTIA Data+ Certification Exam Objectives, page 12

The most likely cause of the issue is that the databases are recording the event in different time zones. A time zone is a region that observes a uniform standard time for legal, commercial, and social purposes. Different time zones have different offsets from Coordinated Universal Time (UTC), which is the primary time standard by which the world regulates clocks and time. For example, UTC-5 is five hours behind UTC, while UTC+3 is three hours ahead of UTC. If an event is being stored in two databases that are housed in different geographical locations with different time zones, it may appear that the event is being logged at different times, depending on how the databases handle the time zone conversion. For example, if one database records the event in UTC-5 and another database records the event in UTC+3, then an event that occurs at 12:00 PM in UTC-5 will appear as 9:00 AM in UTC+3. The other options are not likely causes of the issue, as they are either unrelated or implausible. The data analyst is not querying the databases incorrectly, as this would not affect the time stamps of the events. The databases are not recording different events, as they are supposed to record the same recurring event. The second database is not logging incorrectly, as there is no evidence or reason to assume that. Reference: [Time zone - Wikipedia]