A Tale of Two Castles, Visiting Old San Juan Puerto Rico

Towering over the city, the ancient battlements stand guard. Construction of these immense forts and walls began in the 1500’s by the Spaniards to protect their treasure ships. They finished over 250 years later. San Juan, Puerto Rico is one of many old fort cities that once dotted the Caribbean. Remnants of the massive walls that once surrounded the city remain visible in many parts of old San Juan. The jewels of the city, Castillo San Felipe del Morro and Castillo San Cristobal still loom large. Enter the city by boat and El Morro dominates the horizon. Once docked, a short walk brings guests to San Cristobal. El Morro guarded the bay. Larger and 200 years newer, San Cristobal once guarded the land east of the old city. In the late 1800’s, about a third of San Cristobal was razed to improve traffic flow through the city. The United States added bunkers and artillery during World War 2. Now both castles invite tourists to defend the city with dollars to help keep the economy viable rather than soldiers with weapons repelling the many enemies who threatened the city throughout the centuries.

Both castles are World Heritage Sites, under the protection of the National Park Service. El Morro, as it is referred to, also has a cathedral and an old cemetery with the remains of Ponce de Leon. To the delight of many visitors, iguanas mow the grass at San Cristobal. Quite used to human intrusion, they almost seem to pose for the numerous pictures people take of them.

A stroll through the blue brick cobblestone streets of town reveals colonial architecture, brightly colored buildings, and cats sleeping in fanciful doorways. The blue bricks are a remnant of Spain of the 1800’s. Furnace slag brought over from Spain as ship’s ballast, they make for unique and beautiful streets. Modern cars have some difficulty maneuvering on streets intended for horse and buggy use. They often ride over the curb while turning corners.

Transportation: Your own two feet can get you around Old San Juan if you have the time and the energy. Other options include the hop on, hop off bus, the free Forest Service shuttle, and bike rentals.

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Makler Heidelberg

7 Best Practice Tips To Optimize Your Author Website

As a self-published author, you may think that writing new manuscripts is the most important thing you could focus your attention on. While creating new content for your readers is vital to your success, working on the marketing side of your business is just as important for you to go from barely known to a prominent name in your literary niche.

Along with doing blog tours and email marketing, one of the most effective ways to connect with new readers and keep loyal fans up-to-date is to have your very own author website.

You can think of your author website as your calling card, home base or storefront that gives your prospects a direct way to find out more about you and your work. And the best part is that it’s open 24 hours a day, 7 days a week!

Already have an author website? Don’t sit back and relax just yet.

The only thing better than having a good author website is having a great one that’s fully optimized and designed to take advantage of all the essential features that go into a compelling book promotion website. One that pulls your reader further down the rabbit hole that is your brand and online domain.

Here are tips on how to achieve this in seven practical ways.

Create an Interesting About Me Page

The average person who lands on an author page keeps on reading for one specific reason. They want to know more about the man or woman behind the manuscript. It’s for this reason that every fully optimized author website must have an interesting about me page.

Your about page gives you the chance to share a bit about yourself with a curious prospect or someone who is already a fan of your work but wants to know more about what makes you tick.

If you think your about page is where you should list all your credentials and any awards you’ve won, you’d be somewhat correct. While you can include your accolades, it’s more important to connect with your reader by showing them that you’re a real person just like them.

Feel free to let your guard down and reveal something about yourself you’re your prospects may find interesting, surprising or just plain funny about who you really are.

Add a List of All Your Book Titles

An author website isn’t complete without a page where visitors can find out more about every book you’ve penned.

One marketing truth that has stood the test of time is that it’s much easier to keep a customer than it is to acquire a new one. Based on this fact, setting up a page featuring all of your book titles is a no brainer.

The simplest way to go about this is to list each book and make each title a clickable link that directs your visitor to the sales page related to the specific book.

An even better option is to create a page that features the cover art of each book along with a short blurb describing the contents of each one.

A picture is worth a thousand words, so an eye-catching cover along with a tantalizing tidbit about what lies within the pages of each book is sure to pique the interest of the vast majority of those who stumble upon this vital page.

Add an Email List Sign Up Page

Email marketing is perhaps the most effective marketing tool of modern times. In fact studies show that, for every dollar spent on email marketing, the average return is close to 400%.

This alone makes building a list of prospect emails immensely important. But the benefits don’t end there.

If like many other self-published authors you put your work up for sale on book selling platforms like Nook, Kobo and Kindle you always run the risk of losing potential buyers if your account gets suspended or the platform shuts down for some reason.

By having your own email list, you are free to send marketing messages to your prospects and promote your new and older book releases without worrying about being inconvenienced due to reasons beyond your control.

Include Several Book Reviews

One of the easiest ways to provide a boost of interest in your books and increase sales is by posting what previous readers have to say about your work.

Known as ’social proof‘, book reviews allow potential buyers to read the opinions of unbiased third parties to find out if your titles would be something they would actually be interested in reading.

This is a powerful sales tool that can quickly tip the scales in your favor if a prospect is on the fence about buying one of your books. To make this optimization tactic even more effective, include the name and picture of the reviewer whenever possible.

Post Social Media Share Buttons

Social media sharing is a key factor that facilitates the viral effect that’s responsible for launching much of the works written by self-published authors into the stratosphere.

If you are serious about building a thriving career based on publishing and selling books, creating a presence on social media channels is imperative.

An easy way do this is by putting social sharing buttons in a prominent location on your author website. Do this and you’ll have your fans spreading the word about your book and website in short order.

In addition to having social sharing buttons, make sure that you also have prominent links pointing to your official social media pages on Facebook, Twitter and where ever else your target audience gathers online.

Add To and Regularly Update Your Blog

Along with email marketing, blogging has become known as one of the highest return on investment activities that can be done to promote an offering online, and that includes self-published books!

Blogs are like the daily, weekly or monthly news feed of an otherwise static website.

Along with allowing you to update your fans on new information about your book titles, upcoming events and other important matters related to your brand, your blog works to attract more attention from major search engines like Google.

Blogging on a regular basis helps to gradually increase traffic to your website, which in turn increases traffic to your email lists and book sales pages, which increases your odds of snagging new readers and increasing your bottom line.

The key to making a blog work to improve your traffic and subsequent book sales is to focus on educating, inspiring and entertaining your readers and prospects instead of trying to hard sell them on your books.

By posting regularly and about topics of interest to your audience (that relate to your writing niche) you warm them up to the point where they want to know more about and read everything you have to offer.

Have a Mobile Optimized Website Format

Nowadays more people are viewing web pages on their phones and tablets than on full-sized laptops or desktop screens.

This trend makes it imperative to create your author website using a format that makes viewing your pages on a handheld device as pleasant an experience as viewing it with a much larger screen. This mobile optimization is also known as responsive web design.

By creating your author website with a template optimized for mobile devices, you increase the chances that your page will attract potential readers to your site as well as boost your search rankings in Google and other major search engines.

Use these tips to create a fully-optimized author website. It’s the key to creating a lasting and visible brand by serving as a marketing hub and gathering place for you current and future fan base.

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Makler Heidelberg

Five Jamaican Vacation Activities To Enjoy

The island of Jamaica is one of the top destinations in the Caribbean. Its honeymoon package is second to none is the world. Two of the main reasons for the island being such a lovely vacation destination are the activities that are on offer and the excellent stock of all-inclusive resorts and hotels in the island. The north coast of the island is littered with excellent destinations such as Ocho Rios, Runaway Bay, Montego Bay and Negril. There are other destinations like Kingston, Port Antonio, and Falmouth which are good choices as well. Additionally, the smaller destinations offer some great activities for visitors as well. Here are some activities you will enjoy while visiting Jamaica.

Sports: Jamaica is one of the leading islands for sports and sport facilities in the Caribbean. It’s an excellent place for a sports camp especially in the winter time. There are many hotels that offer world-class golf courses, tennis courts, swimming pools, basketball courts and fitness centers that visitors can enjoy. Also, there are excellent motto sports, mountain bike riding, horse racing, boxing, netball, cricket and soccer facilities that are in close proximity to top hotels and resorts that can be of major benefit to visitors. Additionally, the island possesses many talented sports personnel that can be an asset to visitors sporting endeavors.

Deep Sea Fishing: Jamaica has some of the calmest water in the Caribbean. This is due to the fact that the island is completely surrounded by the Caribbean Sea. Jamaica deep-sea fishing adventures are both fascinating and relaxing experience for visitors. The country’s water possesses a great variety of marine life that makes fishing adventure very rewarding for visitors to the island. There are many resorts and hotels that make arrangement for visitors to enjoy deep-sea fishing through many boat charters and excursion facilities available on the island.

Jamaica Water Sports Activities: The island of Jamaica provides visitors with an opportunity to enjoy water sports second to none in the Caribbean. There are many top resorts that offers waters sports. Some of the top resorts include Beaches Negril Resort, Sunset Jamaican Grande and Rose Hall Resort. Also, there is the Kool Running Water Park in Negril which is a favorite amongst visitors for water sports facility. One of the major water sporting activities that Jamaica offers is surfing. This island offers excellent surfing water for surfers who are just learning to surf. Other major water sports activities that island offer are snorkeling, scuba diving, kayaking, and windsurfing.

Jamaica Site Seeing: A visit to Jamaica without experiencing the interior of the island is almost like not visiting at all. There are a number of excellent places visitor can enjoy when visiting Jamaica. These include Dunn’s River Fall, Seven Miles Beach, Blue Hole Mineral Spring, Rockland Bird Sanctuary, the many craft markets, markets, and great houses amongst others. There are many tours operators throughout the island that can facilitate these activities.

Shopping in Jamaica: Jamaica is one of the most fascinating islands to shop in the Caribbean. A visit to the craft markets or the many markets throughout the island is always an exciting experience. Visitors are sure to have fun with the famous Jamaican accent and the crafty ways vendors go about selling the products. Apart from these are there many excellent duty-free shopping experiences that are offered by many businesses. These businesses often offer many unique Jamaican products that will make excellent souvenirs and gifts for love ones.

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Social Bookmarking – Helping You Generate the Web Traffic You Need

Now if you’ve been involving yourself in the SEO (Search Engine Optimization) business for quite some time, then you would know all too well about the significance that link building serves in the profitability and online visibility of any web marketing business. Obviously, online businesses need a good website that features useful content and information about the services and products that you are offering online. No matter how good your website is or how interesting or how useful your content is though, all of that would certainly amount to nothing if online users can’t even find it online which is why some form of online advertisement is clearly needed. Backlinks are a significant part of implementing such advertisements and one of the most effective methods for building links lies in social bookmarking.

What exactly is social bookmarking?

Social bookmarking as an effective and viable SEO strategy revolves around storing and organizing bookmarks in fairly much the same way as you add sites to your favorites except that in this case, the websites that were bookmarked can be accessed by anyone online. Websites for social bookmarks were initially intended as an online resource that practically anyone could tap into that is until it was discovered that it presents an excellent opportunity for one-way link building. These sites often feature fairly high page ranks which mean they possess relevance and authority in the eyes of major search engines which will certainly benefit your efforts at attaining quality and effective backlinks.

Social bookmarking and its advantages

If you look up several resources online about the subject, you’ll find that among the significant advantages of this particular solution for building links is its accessibility and convenience. You can access your bookmarks from practically any computer connected online. This enables web marketers to reach out a broader range of audience making it an important tool for web marketing.

Another significant advantage of social bookmarking is that it yields a large number of backlinks and generates ample traffic from potential consumers looking for a specific product or service. That and the implementation of effective strategies for building links helps web marketers generate the traffic they need to strengthen their online businesses and create more opportunities for generating profit. Link building is after all a highly competitive and tedious business. If there is to be any chance of success, online businesses need all the leverage they can get in their SEO efforts. Link building through social bookmarking can offer you just that!

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Makler Heidelberg

How to Improve Your Vehicle’s Battery Performance Using Dual Battery Isolator System

Want to improve the efficiency of your battery performance? Investing on a battery isolator is the way to go. Though buying one can put a dent on your budget, it can really help eliminate a lot of problems and hassles when it comes to ensuring a sufficient electric power supply for your car, boat, truck or even airplane.

What is battery isolator?

It is an electrical device that efficiently segregates direct current into other branches, allowing current in one direction in each area that needs power supply. A battery switch allows you to completely discharge one battery without the need of discharging the starting battery. This technology is not only use for vehicles but also for motorized boat. Sometime this technology is called as fisherman friend for they give more life and extend travel distances.

A BSR is the simple and most technologically advanced strategy for automated battery isolation system. The units can be mounted between batteries with a common ground to easily manages the charging process of the batteries but continue to produce isolation between them when the charging origin is inaccessible. The tiny size and rugged design of these units allow a quick setup even for the in-experienced driver.

Smart battery switch are usually used by people who posses large amount of electronics and accessories in the vehicle and boat. The existence of marine battery isolator enables the fisherman to install more lighting in their boat at night while sounds and radio instruments all day. Below are the other best benefits of batter isolator.

More power reserves

This is the primary main benefit of using a dual battery kit. It offers you the ability to charge more than one battery simultaneously from a single power source, without any need of connecting the battery terminals together. The battery isolator ensures that there’s enough power to start the engine, or accommodates high electric current loads.

Many motorists listen to their stereo or use other accessories like computers, lights, radio, and TV without the engine running. This can often result to drained or dead batteries, which can again lead to some other ensuing problems. To avoid that predicament, using a battery isolator is the best solution.

Types of Battery Isolator and Their Benefits

  • Solenoid isolator
  • Diode isolator

Solenoid helps to control the electric current flow between two batteries utilizing high-current relays. One major advantage is that it includes a preservation of voltage across contacts. However, many who have used this type of isolator are saying that it isn’t as reliable as the diode based isolators.

Diode isolator, on the other hand, contains two high-current diodes. They serve as a heat sink that works best for the batteries. Most common example of dual battery systems are smart battery isolator and ATV dual battery system. The setup of this type of battery isolator switch is easy with the help of complete installation kit or system. The best benefit with this type of isolator is that it has a long lifespan with a low amount of maintenance.

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Makler Heidelberg

Gratuity for Wedding Officiants – What to Tip at a Wedding and How to Tip Your Wedding Minister

Many brides and grooms, or their parents, are very shy when it comes to making payments to a wedding professional in person, but they are generally more embarrassed when dealing with their wedding clergy in regards to payment, and especially a giving a gratuity. I have been on both ends of the wedding altar and I can tell you that it’s much easier to deal with than you think and there is a smart way.

Everyone is a bit unsure of what is proper mostly because wedding ministers as a whole have historically dealt with rituals and properness in situations and most folks do not want to cross the line. But remember that wedding professionals deal with this issue on a daily basis and so they understand your uncomfortableness and they have seen it quite a bit. To them, it is part of the work day.

Do I tip? Definitely, yes. How much? It depends, but it is not unusual to double a fee. How? There is a good time to pay the gratuity when you pay the balance of your officiant fee. Why? Because t.i.p. stands for to insure proper service. Your marriage officiant is still holding your marriage license when you part ways (they are required usually to file it themselves). Where? At the signing.

How do you pay and tip with class? It is not so difficult after all. Tipping anyone should be done with joy and gratitude. Consider the following wedding information.

Most officiants charge from $275 to $900 for a wedding ceremony. It all depends on your wedding ceremony location, what things you feel you need from your wedding minister and how busy they are. The busier the wedding minister, the more expensive they will generally be.

Most wedding vendors will ask for a deposit in advance and the remainder to be paid on the day of the wedding. Do remember to make a prompt deposit as wedding professionals do get calls and emails constantly. A typical wedding professional gets anywhere from 10 to 100 requests a day. That is a lot time requests to be juggling. Frankly, the first person to commit by putting down a deposit is the one who wins that time slot.

We recommend that you send the officiant you have chosen the deposit by check or by credit card immediately so that you do have a hold on their time and also so that there is a paper trail. However, in my experience, the balance should be paid by cash.

When you pay the balance it is usually more embarrassing for people since it is in person and there is no „right moment“. But there is.

The best thing to do is to bring an envelope with each wedding vendor name on it and put the remainder in cash in the envelope. If you are in a large wedding, hand these to your best man or the father of the bride (which makes him feel more important) and tell them to distribute the money for you.

Do make sure to pay by the balance you owe your wedding minister in cash or your license may not be filed in time for the check to clear. Even worse, if you are traveling after your wedding and your check bounces, you may find that you are not married by the time you return from your honeymoon. A wedding officiant is required to file your marriage license within a certain amount of time with the county, usually 10 days. If they are paid by check and it bounces while you are in Tahiti then you may have a bit of a problem as that wedding clergy does not know if you will be paying on your bad check.

The best time to pay is at the signing of the marriage license. There is always a shuffling of papers from each person and when the wedding officiant signs it you can easily hand the envelope over with a „Thank you!“

And do not forget the minister gratuity. You can include that in the envelope as well. What is the proper tip for an officiant? $75 – $150 is the proper officiant gratuity and if that seems to be too much to you, consider this: your wedding officiant is probably the least paid of most of the wedding professionals present at your wedding and yet you need that one person at your wedding ceremony more than anyone else there, or else. . . you would not be married. Yes, you do not need to tip a wedding official but think of it this way: it’s good karma and a good way to start your marriage with a positive vibe from the one person who joined you as husband and wife.

Immobilienmakler Heidelberg

Makler Heidelberg

5 Ways to Identify Bot Traffic for Your Website

The ultimate goal of making an online business is to reach to more users. Creating maximum visibility for your website is the key business goal. Web traffic helps take your business, product or service to audiences that are geographically scattered around the world. It also helps in acquiring more users, in generating additional business opportunities and in providing confidence to advertisers to boost their strategies.

Every platform, however, has its dark side. When your online business grows, there is an inevitable possibility that almost half of the web traffic consists of bots. Bot traffic, in simple terms, is the non-human traffic coming to your website from spiders and robots. This traffic deceives marketers into thinking that they have legitimate web users landing on their website but in reality, it is spam, which generally consists of low-quality traffic that will skew your aggregated data.

So how does one even know about the presence of bots in your web traffic? In other words, how can you make sure that your website visitors are humans and not robots?

Brands can identify bot traffic by tracking, monitoring and analyzing the following website metrics:

Traffic Trends

Web traffic usually grows gradually, over a period of time. This growth is dependent on your activities like organic marketing, paid marketing, content quality, etc. Hence if you see a sudden spike in traffic in a day or week, it should automatically ring a bell that it may be non-human traffic. Such traffic skews the usual graph drastically, leading marketers to believe that they actually received heavy traffic to their website.

Bounce Rate

A bot-laden website will exhibit a higher bounce rate. A bounce rate below 50% and between 20-25% is considered acceptable and healthy, depending on the nature of your business. On the same note, there are scenarios where the bounce rates also dip to impractical lows, like 10%, or rise to impractical highs like 95%, which might indicate suspicious bot activities on your website.

Traffic Source

Traffic predominantly comes from three primary varieties of channels or sources -organic, direct and referral. During a bot attack, the influx of traffic will majorly be from direct sources. A healthy and human-driven traffic usually descends from referral and organic sources like social media and search engines, respectively, on which you maximise efforts.

Hits on Pages

These are simple and easy to detect. You can be sure that bots have attacked your website if you see a vast number of hits from a single IP within a very short period of time. These bots will usually flood your website at regular, repeated intervals, which will show an unnatural skew in your usual traffic graph of hits.

Unexpected Geographic Locations

Though visitors coming to your website are geographically scattered, you can still identify bots smartly if your target audience isn’t even remotely close to your business location. If you have customers regularly visiting your website from an ‚x‘ location and suddenly there is a wave of customers coming from ‚y‘ location, that could be a sign of bot traffic.

There are lots of tools available online to detect and filter such bots and to prevent them from returning to your website. A daily or weekly check-up of your website is advisable to monitor and curb bot traffic.

Immobilienmakler Heidelberg

Makler Heidelberg

SQL Window Functions on Data Science Interviews Asked By Airbnb, Netflix, Twitter, and Uber

Window functions are a group of functions that will perform calculations across a set of rows that are related to your current row. They are considered advanced sql and are often asked during data science interviews. It’s also used at work a lot to solve many different types of problems. Let’s summarize the 4 different types of window functions and cover the why and when you’d use them.

4 Types of Window Functions

1. Regular aggregate functions

o These are aggregates like AVG, MIN/MAX, COUNT, SUM

o You’ll want to use these to aggregate your data and group it by another column like month or year

2. Ranking functions


o These are functions that help you rank your data. You can either rank your entire dataset or rank them by groups like by month or country

o Extremely useful to generate ranking indexes within groups

3. Generating statistics

o These are great if you need to generate simple statistics like NTILE (percentiles, quartiles, medians)

o You can use this for your entire dataset or by group

4. Handling time series data

o A very common window function especially if you need to calculate trends like a month-over-month rolling average or a growth metric

o LAG and LEAD are the two functions that allow you to do this.

1. Regular aggregate function

Regular aggregate functions are functions like average, count, sum, min/max that are applied to columns. The goal is to apply the aggregate function if you want to apply aggregations to different groups in the dataset, like month.

This is similar to the type of calculation that can be done with an aggregate function that you’d find in the SELECT clause, but unlike regular aggregate functions, window functions do not group several rows into a single output row, they are grouped together or retain their own identities, depending on how you find them.

Avg() Example:

Let’s take a look at one example of an avg() window function implemented to answer a data analytics question. You can view the question and write code in the link below:


This is a perfect example of using a window function and then applying an avg() to a month group. Here we’re trying to calculate the average distance per dollar by the month. This is hard to do in SQL without this window function. Here we’ve applied the avg() window function to the 3rd column where we’ve found the average value for the month-year for every month-year in the dataset. We can use this metric to calculate the difference between the month average and the date average for each request date in the table.

The code to implement the window function would look like this:

SELECT a.request_date,


AVG(a.dist_to_cost) OVER(PARTITION BY a.request_mnth) AS avg_dist_to_cost



to_char(request_date::date, ‚YYYY-MM‘) AS request_mnth,

(distance_to_travel/monetary_cost) AS dist_to_cost

FROM uber_request_logs) a

ORDER BY request_date

2. Ranking Functions

Ranking functions are an important utility for a data scientist. You’re always ranking and indexing your data to better understand which rows are the best in your dataset. SQL window functions give you 3 ranking utilities — RANK(), DENSE_RANK(), ROW_NUMBER() — depending on your exact use case. These functions will help you list your data in order and in groups based on what you desire.

Rank() Example:

Let’s take a look at one ranking window function example to see how we can rank data within groups using SQL window functions. Follow along interactively with this link: platform.stratascratch.com/coding-question?id=9898&python=

Here we want to find the top salaries by department. We can’t just find the top 3 salaries without a window function because it will just give us the top 3 salaries across all departments, so we need to rank the salaries by departments individually. This is done by rank() and partitioned by department. From there it’s really easy to filter for top 3 across all departments

Here’s the code to output this table. You can copy and paste in the SQL editor in the link above and see the same output.

SELECT department,


RANK() OVER (PARTITION BY a.department

ORDER BY a.salary DESC) AS rank_id


(SELECT department, salary

FROM twitter_employee

GROUP BY department, salary

ORDER BY department, salary) a

ORDER BY department,

salary DESC


NTILE is a very useful function for those in data analytics, business analytics, and data science. Often times when deadline with statistical data, you probably need to create robust statistics such as quartile, quintile, median, decile in your daily job, and NTILE makes it easy to generate these outputs.

NTILE takes an argument of the number of bins (or basically how many buckets you want to split your data into), and then creates this number of bins by dividing your data into that many number of bins. You set how the data is ordered and partitioned, if you want additional groupings.

NTILE(100) Example

In this example, we’ll learn how to use NTILE to categorize our data into percentiles. You can follow along interactively in the link here: platform.stratascratch.com/coding-question?id=10303&python=

What you’re trying to do here is identify the top 5 percent of claims based on a score an algorithm outputs. But you can’t just find the top 5% and do an order by because you want to find the top 5% by state. So one way to do this is to use a NTILE() ranking function and then PARTITION by the state. You can then apply a filter in the WHERE clause to get the top 5%.

Here’s the code to output the entire table above. You can copy and paste it in the link above.

SELECT policy_num,








ORDER BY fraud_score DESC) AS percentile

FROM fraud_score) a

WHERE percentile <=5

4. Handling time series data

LAG and LEAD are two window functions that are useful for dealing with time series data. The only difference between LAG and LEAD is whether you want to grab from previous rows or following rows, almost like sampling from previous data or future data.

You can use LAG and LEAD to calculate month-over-month growth or rolling averages. As a data scientist and business analyst, you’re always dealing with time series data and creating those time metrics.

LAG() Example:

In this example, we want to find the percentage growth year-over-year, which is a very common question that data scientists and business analyst answer on a daily basis. The problem statement, data, and SQL editor is in the following link if you want to try to code the solution on your own: platform.stratascratch.com/coding-question?id=9637&python=

What’s hard about this problem is the data is set up — you need to use the previous row’s value in your metric. But SQL isn’t built to do that. SQL is built to calculate anything you want as long as the values are on the same row. So we can use the lag() or lead() window function which will take the previous or subsequent rows and put it in your current row which is what this question is doing.

Here’s the code to output the entire table above. You can copy and paste the code in the SQL editor in the link above:

SELECT year,



round(((current_year_host – prev_year_host)/(cast(prev_year_host AS numeric)))*100) estimated_growth


(SELECT year,


LAG(current_year_host, 1) OVER (ORDER BY year) AS prev_year_host


(SELECT extract(year

FROM host_since::date) AS year,

count(id) current_year_host

FROM airbnb_search_details

WHERE host_since IS NOT NULL

GROUP BY extract(year

FROM host_since::date)

ORDER BY year) t1) t2

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Makler Heidelberg

Squash Strings – Dynamics and Performance

The performance of your squash racquet is largely dependent on your squash strings. By changing the characteristics of your squash strings, you can improve different aspects of your performance, or tailor your racquet setup to your style of play. There are different dynamics and features to choose from, so choosing the perfect squash strings is essential to matching your squash equipment to your method of play.

Squash string tension can be used to your advantage regardless of your style. If you’re a player who yearns for a more powerful shot, then a loose tension will best fit your needs. For those who are already comfortable with their power, and looking for more control or accuracy, then tightening up your strings is the right way to go. Squash string thickness, often referred to as gauge, is measured in millimetres by diameter. Using a string with a thinner diameter will offer more power. Thinner strings provide more power due to a catapult effect that is created, as thin strings, allow the string bed to bend and manipulate inwards and outwards. Stringing up with a thicker string, will not only provide additional control, but thick strings are also more durable and will last much longer before replacements are needed. The increased accuracy is provided by a much firmer and less palpable string bed.

It’s important to remember that your squash strings will lose tension over time. For those who opt for tighter strings, you may notice your control and accuracy decreases over time, and this can be, in part, down to your strings losing tenacity. For looser strings, as the strings become more relaxed, you will begin to lose the power in your shots you originally had. These issues can be easily resolved by maintaining your equipment and replacing or tightening strings regularly. If you’re a beginner mastering your game, or a pro polishing off your skills, string tension should always be an element of your equipment you maintain regularly. It’s estimated that string tension will reduce up to 10% in the first day of being strung, and more so over time, due to use during play.

Choosing the right squash strings for your racquet is considered to be one of the most important factors of your racquet setup. Ensure you have the right tension and gauge for your style of play and maintain regular upkeep to ensure the consistency of your game.

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Makler Heidelberg